Monetization of Environmental Impacts of Roads
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Chapter 3--Environmental Impacts

A wide range of environmental impacts result from stressors produced by the construction, maintenance and use of roads. Roads can: In the evaluation of transportation projects, credible estimates of environmental costs can be achieved only through an understanding of all the environmental implications of the options being considered.

This chapter summarizes the environmental stressors and impacts of road transportation that are then costed in Chapter 4. Each of the major stressors is identified and the type of damage that results is discussed. Where sufficient information is available, indirect as well as direct impacts are included.

3.1 Air Pollution Road transportation produces air emissions directly from road construction and vehicle operation, and indirectly from vehicle manufacture and operation, fuel extraction, production and distribution, and manufacture of construction materials and machinery. The indirect emissions can be a sizable fraction of total vehicle emissions. For example, the energy embodied during manufacturing in an average automobile is 10% to 14% of its total lifetime fuel consumption (Warner and Glenys 1991). Research on embodied emissions is limited, so this report focuses primarily on direct emissions and emissions generated during fuel production and distribution. However, since the energy used in metal production and other industrial processes is primarily fossil-fuel based (including electricity generated from coal or petroleum products), embodied emissions are probably significant.

Vehicle operating emissions include:

These pollutants are emitted from the tailpipe, from the engine and fuel supply system, and from brake linings, clutch plates and tires. The quantity of pollutants emitted by a vehicle depends on its mass, operating conditions, fuel type (gasoline, diesel, alcohol, hydrogen, etc.), fuel formulation (oxygenated gasoline, low-sulphur diesel), engine type and age, pollution control devices, driver behaviour and level of maintenance.

Several of these emissions are greenhouse gases, which contribute to global warming. Vehicle air conditioners and truck refrigeration units contain CFCs, which are greenhouse gases, and ozone-depleting substances, which damage stratospheric ozone when released.

Some road construction activities, such as asphalt-mix preparation and laying, generate emissions as diverse as vehicle engines, but in smaller quantities. Local impacts of these emissions during construction may be large. Road construction and usage also produce dust and smaller particles.

3.1.1 Transportation Sources of Air Pollution

Share of Road Transportation in Total Emissions from Human Activities

Transportation is responsible for a large share of energy use. Consequently, motor vehicle operation contributes a substantial portion to total emissions from human activities. Carbon monoxide from vehicle exhaust is the largest contributor, accounting for more than half of total CO emissions. Vehicles also contribute nitrogen oxides in large quantities. VOCs in vehicle exhaust account for about a third, CFCs and CO2 for about a quarter each, and SOx for a fifth of the total from all sources. The above statistics do not include embodied emissions.

Table 3.1 Contribution of Motor Vehicles to Air Pollution in Selected Cities
% Share of Road Transportation

1000 t

% Total
Mexico City 1987
Los Angeles (a) 1982
(b) 3,391
Phoenix 1986
(c) 1,240
London 1978
Athens 1976
Munich 1975
Osaka 1982
Gothenburg (a) 1980
Notes: Source: Faiz (1990). n/a = not available; PM = particulate matter.

a. Percent shares apply to all transport. Motor vehicles account for 75-95% of the transport share.

b. Excludes particulate matter.

c. Includes 490,000 tonnes of dust from unpaved roads.

Faiz (1990) compiled the contribution of motor vehicles to air pollution in selected cities (Table 3.1). CO2 is not included, but the table clearly shows the large contribution of road transportation to air pollution in most of the cities studied. The composition of vehicular emissions differs between cities. In Hong Kong, for example, a large fraction of urban traffic is composed of goods vehicles, taxis, and buses that almost exclusively burn high sulphur diesel fuel (Rusco and Walls 1995). In Europe, the proportion of diesel-fuelled cars is significantly higher than in Canada and the US. In Vancouver, a large part of the transit bus fleet consists of electric trolleys, which draw power from hydroelectric plants and do not contribute to local pollution. During peak electricity demand periods, however, when extra power has to be provided by a fossil fuel power generating plant located in the region, the trolleys do contribute to both local and regional air pollution.

Present emission inventories are not absolute, and some emissions (particulates, for example) are not sufficiently understood. Some emissions are transformed by chemical reactions into more damaging pollutants. For example, NOx and VOCs react to form ground-level ozone, SOx and NOx convert to acid rain compounds, and CO changes to CO2,, a greenhouse gas. SOx and NOx also form secondary fine particulates. A number of technological solutions to vehicle emission problems have been, or are being, proposed, but they are not without their own problems.

Embodied Emissions

Air polluting emissions embodied in the full life-cycle of a transportation system are significant. Upstream emissions are generated during the production of materials and energy used in vehicle manufacture and assembly; in transportation and retail of vehicles and parts; and during similar phases of the life cycles of construction materials before their end use in transportation infrastructure. Fossil fuel exploration, production, and distribution—and production of other forms of automotive energy such as electricity—also generate emissions. Since the upstream emissions may take place in a different airshed than the tailpipe emissions, the embodied emissions should, in general, be charged at a different shadow price from location-specific emissions, such as particulate matter (PM), CO, SOx, NOx and VOCs, depending on local ambient air concentrations and dose-response relationships.

DeLuchi (1991) has worked out a comprehensive accounting for CO2, methane, N2O and other greenhouse gases at various stages of the vehicle and fuel cycles. A gasoline-fueled light-duty vehicle generates almost one-third of its total emissions, in terms of CO2-equivalents, upstream. This means that for the air emissions generated by driving the vehicle, almost one-half have already been emitted prior to burning the gasoline in the engine. For heavy vehicles, the multiplier is smaller.

Table 3.2 Methane Emissions from Upstream Oil and Gas Operations in Alberta
Methane Emissions

kilotonnes (kt)

% Total
Drilling, well servicing 9 1.11
Gas production 297 37.86
Conventional oil production 88 11.19
Heavy oil production 199 23.35
Crude bitumen production 19 2.43
Gas processing 71 9.09
Product transmission 38 4.78
Accidents and equipment failures 64 8.19
Alberta upstream oil and gas (a) 785 100.00
Notes: (a) Emissions from heavy oil upgrading, oilsands mining and processing, and fuel consumption in oilfield construction and transportation are not included.

Source: Picard et al. (1992) in Jaques (1992).

Table 3.2 demonstrates the importance of considering emissions embedded in resources used by transportation. Methane emissions from oil production, for example, are 25 times higher than methane emissions from the combustion of fuels produced from the oil (see Table 3.9). The Alberta upstream emissions of methane constituted 71% of the total Canadian upstream methane, and 21% of all Canadian methane from human activities in 1990. Natural gas distribution alone averages almost 3 L of leaked gas per 1000 L of gas transmitted (Jaques 1992). On a CO2-equivalency basis, the Alberta methane accounted for as much as 5% of the contribution of CO2 from fossil fuel burning in Canada in 1990.

Differences Between Vehicles and Operating Modes

Internal combustion engines, when running cold (the first five to eight kilometres of driving an average car after cold start) produce greater emissions than a warm engine, including CO2, for the reason of 5 to 10% greater fuel consumption by a colder engine compared to a warm one. Catalytic converters are unable to process the exhaust produced at a large rate during rapid acceleration from a stop, so they permit more methane and nitroux oxide out the tailpipe.

Hansson and Leksell (1989) compare emissions of NOx, HCs and SO2 from major vehicle types in urban and rural driving (Table 3.3). Urban driving of light vehicles produces about twice as much hydrocarbons-per-kilometre driven, as does rural driving of the same vehicles. The city bus, although it has a smaller engine, is as bad as the heaviest truck because of more frequent stops. Truck emissions differ only slightly between urban and rural driving, except for the trucks in the 3.5 to 9.5 t GVW class.

Table 3.3 Emission Rates of Motor Vehicles in City and Rural Driving
(grams per vehicle-kilometre driven)
Urban Driving
Rural Driving
Vehicle and Fuel Type
Car, gas no catalytic converter 2.5 6.1 0.0 2.5 2.9 0.0
Car, gas catalytic converter 0.7 0.4 0.0 0.4 0.2 0.0
Car, diesel 0.7 0.6 0.3 0.6 0.3 0.3
Utility vehicle, gas 4.0 6.4 0.0 3.7 4.9 0.0
Utility vehicle, diesel 1.4 0.1 0.7 1.4 0.1 0.7
City bus 26.0 2.6 1.7
Other large bus 18.5 2.0 1.3 13.5 1.7 1.1
Truck, gas 4.6 8.9 0.0 4.1 7.4 0.0
Truck, diesel (GVW):            
3.5-9.5 t 3.8 0.8 0.9 3.3 0.6 0.9
5-13.5 t 11.0 1.9 1.0 11 1.9 1.0
13.5-18 t 13.8 1.6 1.2 13.8 1.6 1.2
18-20 t 15.3 1.4 1.3 15.3 1.4 1.3
20-24 t 16.4 1.3 1.4 16.4 1.3 1.4
over 24 t 21.1 1.8 1.9 21.1 1.8 1.9
Notes: NA = not applicable. GVW = gross vehicle weight. Source: Hansson and Leksell (1989)
Intermodal Comparisons

Compared to the other modes of transportation, road vehicles are severe polluters because of the relative inefficiency of road vehicles per unit of transportation work. Jaques (1992) estimated that in 1990, direct emissions of greenhouse gases from Canadian road transportation accounted for over 80% of the total for all transportation modes (Table 3.9). Lamure and Lambert (1993) provide an example analysis of the European high-speed passenger train versus other transportation modes. They conclude that almost all pollutants would be reduced substantially by diverting road and air traffic to rail; only total SO2 emissions would increase.

A recent study by Transport Concepts (1994) used Canadian data to compare emissions from goods transportation by truck and train (Tables 3.4 and 3.5). The superior fuel efficiency per tonne-km hauled by train and associated low emissions of train compared to truck are obvious. This is in spite of lower NOx and PM emissions per litre of fuel burned by truck. Sypher (1992) found that a 2.2% shift in freight traffic from train to truck between 1985 and 1989 caused a 4% to 7% increase in emissions.

Table 3.4 Emissions for Canadian Freight Train and Truck Engines
(grams per litre of fuel burned)
Engine Type
Truck 1990 29.26 75.89 6.36 2.93
2 674
Train 1990 54.55 10.51 2.73 1.72
2 700
Truck 1995 24.42 75.89 6.36 0.48
2 674
Train 1995 52.79 5.28 2.11 1.32
2 674
Notes: Truck engine emissions are legal limits prescribed by Environment Canada. Train engine emissions are test results from the Association of American Railroads. Source: Khan (1991)
Table 3.5 1995 Environmental Performance of Canadian Freight Train and Truck





















- semi-truck 31.5 19.38 0.55 1.75 0.146 0.012 61.38 1.98 0.65
- B-train 44.2 17.60 0.51 1.58 0.138 0.011 56.00 2.04 0.65
- piggyback 31.5 6.67 0.42 0.06 0.017 0.010 21.17 0.00 0.60
- container 27.8 5.85 0.36 0.03 0.014 0.009 18.52 0.00 0.60
- box car 88.5 5.56 0.38 0.03 0.014 0.008 17.67 0.00 0.36
- hopper car 70.0 4.08 0.28 0.05 0.014 0.008 12.90 0.00 0.60
Notes: Data are for the best available equipment expected by 1995.

Emissions are given in grams per tonne-kilometre hauled.

Source: Transport Concepts (1991)

Dobes (1995a) compared greenhouse gas emissions from the non-motorized and steam-propelled transportation of the year 1900 with the motorized transport in the year 2000 in Australia. The use of the internal combustion engine itself has not contributed disproportionately to greenhouse emissions in the transport sector. An economy of size similar to that of today would not have generated a significantly lower quantity of greenhouse gases had the motor car not replaced animals and steam from 1900.

3.1.2 Types of Emissions

Nitrogen Oxides

The most relevant nitrogen oxides (NOx ) are nitric oxide (NO), nitrous oxide (N2O), and nitrogen dioxide (NO2). While emissions vary according to vehicle type and use, transportation is responsible for a large proportion of total emissions in Canada (Figure 3.1). Regional and local differences from the national average are due to climatic, vehicle usage and economic sector differences. In urban areas, transportation accounts for the majority of NOx emissions.

NO is produced in the greatest quantity during combustion of fuels. It has virtually no direct affect on human health, but converts to nitrogen dioxide, which reacts with volatile organic compounds to produce ozone. NO2 irritates the respiratory system, causes bronchitis and pneumonia, and with prolonged exposure, particularly in young children, increases susceptibility to viral infections such as influenza (Moffet and Miller 1993). These health impacts are most prevalent in urban areas.

Figure 3.1 Contribution of Canadian NOx Sources

Source: Transport Canada and Environment Canada (1989)
N2O is several hundred times stronger greenhouse gas than CO2. Skandia (1992) found that cold starts are responsible for 50% to 70% of NOx emissions in Sweden. Recent evidence from Environment Canada has also linked vehicle catalysts to nitrous oxide emissions (Ballantyne et al. 1994). The catalytic reduction process during highway driving creates about twice as much N2O as uncatalyzed combustion. Urban driving, characterized by cooler engines, produces N2O emissions at twice the rural driving rates, where highway driving and hence warmer engines are typical. As the population of catalyst-equipped vehicles increases, so does the contribution of N2O to global warming.

NOx also contribute to the formation of secondary fine particulate matter in the air and to acid precipitation. NO2 gas plays a special role in visibility problems: it absorbs blue light, creating the yellow to reddish-brown appearance of urban smog.

Volatile Organic Compounds

Volatile organic compounds (VOCs) are from the fractions of fuels and lubricants with lower boiling points and from partially combusted fuels. Benzene, toluene, ethylene and xylene are all VOCs emitted in the exhaust of cars. Although most VOC pollutants are emitted when the vehicle is running (running losses), evaporative emissions of hydrocarbons are also significant after an engine is stopped and the engine heat causes evaporation from the carburetor and fuel tank (hot soak evaporative losses). Diurnal evaporative losses result from normal temperature changes causing the air-fuel mixture in the fuel tank to expand and expel vapour.

Motor vehicles emit about 10% of hydrocarbon pollutants from running losses, 30% from other evaporative losses, and 60% from the exhaust (BTCE 1994). Significant amounts of VOCs are also emitted into the atmosphere during refuelling and the production and transport of fuel (Moffet and Miller 1993). Most hydrocarbon emissions are produced by car engines equipped with catalytic converters when running cold after start (Skandia 1992).

VOCs react with NOx to form ground-level ozone. Some VOCs, like benzene, are carcinogenic. Others are relatively non-toxic, but may produce unpleasant effects such as drowsiness, eye irritation, coughing, sneezing and symptoms akin to drunkenness (OECD 1986 in Moffet and Miller 1993). Non-methane VOCs are also a minor contributor to global warming, while methane itself is a major contributor.

Sulphur Oxides

Transportation produces a relatively small portion of total SOx emissions, but vehicle contributions of this pollutant are high in urban areas, where they have the greatest impacts. Contribution of SOx emissions from vehicle manufacturing is significant. Steel and other metals production produce large amounts of SOx. If high-sulphur coal is used to produce alternative fuels such as methanol or power for electric vehicles, transport-related SOx could increase (Moffet and Miller 1993).

SOx and the fine particulate products of their transformation—sulphates and acid aerosols—cause a variety of negative impacts on people and the environment. This includes direct health damage, mainly related to the respiratory system, which is most severe for asthmatic children. SO2 emissions also cause reduced visibility, corrosion of materials, reduced agricultural production and soiling. SOx emissions are a major contributor to acid precipitation. One beneficial impact is the cooling effect of aerosols resulting from SOx emissions. The cooling has offset a significant part of the greenhouse warming over the northern hemisphere, where SOx pollution is most severe.

Carbon Monoxide

When carbon or hydrocarbon fuels are burned with insufficient oxygen some of the carbon is incompletely oxidized and forms carbon monoxide (CO). CO is a colourless, tasteless, poisonous gas that contributes to ground-level ozone formation and converts to methane. Engines equipped with catalytic converters and starting cold emit 90% of all CO emitted by cars in Sweden (Skandia 1992).

Exposure to high concentrations of CO can have negative health effects (Halvorsen and Ruby 1981), such as impaired perception and thinking, slow reflexes, drowsiness and unconsciousness (Mitchell 1991). CO health effects are significant primarily to smokers and people who are exposed to high concentrations at work. CO concentrations can exceed World Health Organization limits in confined city streets carrying heavy traffic and in poorly ventilated spaces where internal combustion engines operate (Mitchell 1991).

Particulate Matter

Transportation activities generate particles ranging from relatively large and visible ones, such as smoke and road dust, to microscopic ones. While the larger particles are a cleaning nuisance, particles smaller than 10 µm (denoted as PM10) are the most harmful, because they stay in the atmosphere for several weeks even in the rainy season, are inhalable and can penetrate human, animal and plant tissue. The finest particle fractions (PM2.5) contain both solids and aerosols (tiny droplets suspended in the air). Wind can carry them from urban centres into suburbs, and they can penetrate into buildings. Aerosols are created in the atmosphere from various substances, such as VOCs, SO2 and NOx.

Seaton et al. (1995) pointed out that it is not necessarily the concentration of particulates in the air, but the ultra-fine nature of the urban particulate cloud that is responsible for harmful effects. A particulate concentration of 100 mg to 200 mg in 1 m3 of urban air may contain up to 1 million nanometre-sized particles per millilitre. Compared to the 1940s and 1950s, the air in London and other cities in the United Kingdom is apparently cleaner now, following the 1956 UK Clean Air Act. The Act significantly reduced the use of coal, the major industrial and domestic fuel. The high incidence of smog has abated, but deaths and ill-health related to air quality have not diminished owing to the increase of fine particulate emissions from motor vehicles.

Composition of particles ranges from road surface materials, tire rubber, carbon and vehicle brake lining to organic compounds from fuel, metals from the wear of vehicle parts, and sulphuric acid aerosols. The finer fractions contain more toxic trace elements than the coarse fraction. The harmful substances (many of them mutagenic and carcinogenic) may either stand alone as separate particles, or they may be adsorbed onto otherwise-inert core particles. Before they precipitate to the ground, particulates have typical life spans of 7 to 40 days, unaffected by rainfall. Recent research indicates that particulate pollution from motor vehicles causes a relatively high incidence of mortality (Dockery et al. 1993, Dockery and Pope 1994, Seaton et al. 1995).

Table 3.6 Particulate Emission Rates of Motor Vehicles in City Driving
Vehicle and Fuel Type
Car, gasoline (no catalytic converter)  0.05
Car, gasoline (catalytic converter)  0.005
Car, diesel 0.3
Utility vehicle, gasoline 0.04
Utility vehicle, diesel 0.44
City bus 1.0
Other large bus 1.0
Truck, gasoline 0.06
Truck, diesel (GVW):  
3.5-9.5 t 0.75
9.5-13.5 t 1.2
13.5-18 t 1.5
18-24 t 1.6
over 24 t 1.7
Notes: GVW = gross vehicle weight; g/vehicle-km = grams per vehicle-kilometre driven

Source: Hansson and Leksell (1989)

Emissions of particulates differ between fuel types and engine types. Hansson and Leksell (1989) compiled particulate emission rates for city driving of vehicles (Table 3.6). The large difference in emission rates with and without catalytic converters in gasoline car engines and between gasoline and diesel engines is evident. However, there is room for improving diesel engine particulate emission rates. European diesel cars, for example, have lower emission rates of particulates than the diesel cars available in Canada.

The high particulate emission rate for buses is disturbing, considering that public transit is the future alternative to automobile use in urban areas. The emission rate for a bus is equivalent to that from 20 gasoline cars without catalytic converters, or 200 cars with catalytic converters, or about 3 diesel cars. Canadian transit agencies purchase buses in large quantities and typically keep them for 15 to 20 years. The harmful effects of urban traffic particulates may justify retrofitting the engines of existing bus stocks to reduce emissions.

Carbon Dioxide and Other Greenhouse Agents

Greenhouse gases warm up the earth’s atmosphere by trapping solar heat (IPCC 1994; Environment Canada 1993a). The greenhouse effect is necessary to make the earth habitable, but increasing concentrations in the atmosphere of greenhouse gases from human activities threaten to cause significant climatic change and resulting ecological turmoil in future decades. Fossil fuel and wood burning have added 25% to the total atmospheric CO2 since the beginning of the Industrial Revolution, but most of this amount has been released in the past 50 years.

The flux of carbon dioxide to the atmosphere is also affected by how land is used. In previous centuries, it was mainly in the world’s temperate regions that the area of forests decreased and thereby contributed to increased CO2 concentrations. Today, it is mainly the felling of the tropical rain forests that is augmenting the net flux of non-industrial carbon dioxide to the atmosphere. Some one-fifth of all CO2 emissions from human activities now can be attributed to deforestation, while the balance (about 22 billion tonnes annually) comes from fossil fuel combustion.

Carbon dioxide accounts for most of the enhanced greenhouse effect. The remainder is caused by the other greenhouse gases: methane, nitrous oxide, ozone, CFCs and HCFCs. Their collective greenhouse effect may add significantly to the warming expected from CO2 alone. This is because of their substantially higher greenhouse power (or radiative forcing) compared to CO2. Water vapour is also a greenhouse gas, but human-generated contributions are insignificant compared to the natural water vapour cycles in the atmosphere.

The contribution of greenhouse gases to global warming, called global warming potential (GWP), is measured in comparison to the contribution made by CO2, defined as 1.0 (IPCC 1994). The GWP of various trace gases is shown in Table 3.7. The disproportionately large GWP of halocarbons over both short and long time horizons is striking. On a CO2-equivalent basis, fuel end-use in transportation contributes about half of the total human-generated N2O, a quarter of the CO2, and a fifth of CFCs’ global warming potential, but only a small fraction of methane (Figure 3.2).

The warming effect of greenhouse gases is partially offset by a cooling effect of aerosols (IPCC 1994). Aerosols are fine airborne particles created in the atmosphere through transformation of sulphates. Aerosols cool the atmosphere directly by absorbing and scattering solar radiation, and indirectly by acting as nuclei on which cloud droplets form. Overall, aerosols may be providing a significant offset to global warming, although they are targeted for abatement as local and regional pollutants generated by combustion of fossil fuels and by burning of biomass.

Table 3.8 summarizes the contribution of different greenhouse-gas sources in Canada, excluding the still-unknown contribution of land use changes. Road transportation is a major source, responsible for about one-quarter of non-biomass emissions of CO2. The other transportation modes add insignificant amounts of CO2 by comparison. For methane, landfills and livestock are much more serious offenders than transportation. Over a long time period, the present contribution of methane and nitrous oxide from transportation would add about 10% to the global warming potential of CO2.

Table 3.7 Global Warming Potential Relative to CO2
Trace Gas
Global Warming Potential over Time Horizon
20 years
100 years
500 years
CO2 ~ 1 1 1
Methane (CH4)
14.5 ± 2.5
62 24.5 7.5
Nitrous Oxide (N2O)
290 320 180
CFC-11 (CFCl3)
50 ± 5
5 000 4 000 1 400
CFC-12 (CF2Cl2)
7 900 8 500 4 200
HCFC-22 (CF2HCl)
4 300 1 700 520
300 93 29
H-1301 (CF3Br)
6 200 5 600 2 200
HFC-23 (CHF3)
9 200 12 100 9 900
Notes: Global warming potential (GWP) is the ability of a substance to contribute to the greenhouse effect; it is a relative unit, measured against CO2, which has a GWP of 1.0. No single lifetime for CO2 can be defined. Typical uncertainty is ± 35% relative to the CO2 reference. GWPl of methane includes the indirect effects from the production of tropospheric ozone and stratospheric water vapour. Source: IPCC (1994).
Figure 3.2 Relative Contribution of Greenhouse Gas Emissions to Global Warming

Source: McRobert et al. (1991).
N2O emissions are 2 to 5 times higher for engines fitted with catalytic converters (UK Department of Environment 1994, Ballantyne et al. 1994, Skandia 1992). N2O is also produced by fossil-fuel power plants supplying energy for transportation and related activities. N2O is broken down in the stratosphere by sunlight, but it has a long lifetime. While N2O has a direct greenhouse-gas effect and NOx contribute indirectly through ground-level ozone formation, they also lead to an increase in the oxidizing capacity of the atmosphere and thus a decrease in the concentration of methane. Thus enhanced levels of NOx have opposing effects on the abundance of two greenhouse gases, ozone and methane, and it is possible that the net effect may be beneficial, although it is uncertain at present (UK Department of Environment 1994).  
Table 3.8 Summary of 1990 Canadian Greenhouse Gas Emissions, kilotonnes per year
Industrial Processes:      
- Upstream Oil and Gas Production
7 567
1 100
- Cement and Lime Production
7 666
- Other
13 620
Subtotal Industrial Processes
28 856
1 261
Fuel Combustion (b):      
- Stationary Sources
286 607
- Transportation (Mobile Sources)      
49 019
Light-duty Gasoline Trucks 
23 094
Heavy-duty Gasoline Trucks
2 235
7 292
Light-duty Diesel Trucks
Heavy-duty Diesel Trucks
21 410
Other Diesel Engines
14 363
Subtotal Road Vehicles
117 697
13 137
6 315
7 782
Subtotal Transportation Sources
144 931
Subtotal Fuel Combustion
431 538
Total Anthropogenic Excl. Biomass
460 394
1 292
Biomass Sources:      
- Wood Waste and Other Incineration
8 870
- Landfills
3 870
1 405
- Livestock and Manure
34 600
1 000
- Fertilizer Use
- Prescribed Burning
8 600
- Anaesthetics
Total Anthropogenic, Exclusive of Land Use
516 334
3 737
Notes: --- = not applicable. ??? = not available. Source: Jaques (1992)
Ozone, regardless of where it is located in the atmosphere, is also a greenhouse gas. Ground-level (tropospheric) ozone, the component of urban smog, is formed from vehicle emissions and other human activities. Stratospheric ozone is created naturally and it protects the life on earth from harmful ultraviolet radiation. Non-methane hydrocarbons CO and NOx while not important greenhouse gases in their own right, can have indirect effects on radiative forcing. The photochemical reactions involving them lead to changes in the concentrations of ground-level ozone and atmospheric oxidants, so that high levels of these pollutants result in enhanced concentrations of both ozone and, to a lesser degree, methane, HCFCs and HCFs, and hence they have a positive indirect greenhouse effect (UK Department of Environment 1994).

The most prevalent halocarbons with greenhouse properties are CFCs. CFCs play a dual role: in the lower atmosphere they heat, but in the stratosphere, they become the primary source of chlorine, which degrades the earth’s ozone shield. Their global warming potentials are up to several thousand times stronger than CO2. So effective are CFCs at trapping heat that they have been credited with about 25% of the warming potential added to the lower atmosphere during the last decade. However, the direct greenhouse effect of CFCs was recently discovered to be offset by the loss of stratospheric ozone, a natural greenhouse gas. CFCs’ net contribution to global warming may thus be neutral (IPCC 1994, WRI 1994). However, CFCs are being replaced with non-ozone-depleting HCFCs and HFCs, which have very long lifetimes and high global warming potentials.

Road transportation currently contributes about a third of human-generated CO2 in British Columbia, or about half of CO2 from sources excluding agriculture and forestry (Table†3.9). By 2010, road transportation’s share will drop to 28% of the total human-generated CO2, but will increase in absolute terms. The table shows energy end-use in British Columbia and therefore does not account for the energy embedded in the full fuel, vehicle and transportation system cycles.

Table 3.9 End-Use CO2 Emissions in British Columbia by Sector, kilotonnes
Industrial 10 285 10 745 16 115
Residential 6 153 7 079 9 925
Commercial 3 270 4 273 6 186
- road gasoline 9 914 10 298 10 779
- road diesel 3 019 3 518 4 566
- road natural gas and propane 327 346 414
Subtotal Road 13 260 14 162 15 759
- rail diesel 1 311 1 148 1 332
- marine diesel 882 906 1 019
- marine heavy fuel 1 237 1 300 1 725
- subtotal marine 2 118 2 206 2 744
- aviation gas & turbo 2 465 2 610 3 261
- natural gas automotive fuel 55 67 97
Subtotal Transportation 19 209 20 193 23 193
Total 38 918 42 291 55 419
Notes: Estimates by Ward (1994) based on MEMPR (1993) energy consumption data, using emission factors for each type of fossil fuel. Domestic portion of CO2 stripped from raw natural gas in British Columbia and vented to atmosphere is included. About 3000 kt of CO2 from lime kilns, aluminum smelting, CO boilers and miscellaneous chemical industries are not included. Road transportation emissions are likely understated. Embodied emissions are not included.


Stratospheric Ozone Depleters

A layer of ozone molecules in the upper atmosphere (stratosphere) protects life on earth from the burning rays of the sun. During the 1970s, scientists warned of ozone depletion from industrial halocarbons discharged into the atmosphere. Industrial halocarbons are human-made, non-toxic, inert gases. Halocarbons are a large class of carbon compounds containing fluorine (F), chlorine (Cl) and bromine (Br). Since scientists reported a hole in the ozone layer above Antarctica in 1985, ozone depletion has remained on the top of international environmental agendas.

CFCs account for over 80% of total stratospheric ozone depletion. CFCs are used as a blowing agent to produce foam products (which are used to make vehicle seats and insulation, among other things), as a solvent for degreasing parts and cleaning electronic components and fuel injectors in vehicle manufacture, and as refrigerants in air conditioners of vehicles and refrigerators in trucks that transport perishables. About 23% of Canadian CFC consumption is in domestic automobiles (Environment Canada 1993), one of the largest uses of these chemicals.

Leaking automobile air conditioners are a major source of CFC releases from transportation activities. There are about 13 million automobiles in Canada and approximately 60% of these vehicles are equipped with air conditioners. At an average charge of 1.7 kg of CFCs per vehicle, that is 14 000 t on the Canadian roads today (Environment Canada 1993b). Out of 14.8 million vehicles in Canada, 68% of cars and 47% of trucks have air-conditioning (Watershed Sentinel 1995). In British Columbia, significantly smaller percentage of the road vehicle fleet is air-conditioned, presumably because of milder climate (Table 3.21). Newer vehicle designs, production methods and maintenance procedures may significantly reduce emissions of ozone-depleting substances.

The ozone-destroying power of a compound is called its ozone depletion potential (ODP). It is measured against CFC-11, which has an ODP of 1.0. Bromine-containing halocarbons have very high ODPs (Table 3.10).

Table 3.10 Ozone Depletion Potential of Selected Halocarbons
Ozone Depletion Potential
Atmospheric lifetime (years)
CFC-11 CFCl3
CFC-12 CF2Cl2
CFC-113 CF2ClCF2Cl
CFC-114 CF2ClF2Cl
0.6 - 0.8
Halon-1211 CF2Br2Cl
2.2 - 3.5
Halon-1301 CBrF3
7.8 - 16.0
80 - 110
Halon-2402 C2F4Br2
5.0 - 6.2
23 - 28
0.04 - 0.06
15 - 20
0.02 - 0.16
1 - 2
HCFC-141b CH3CFCl2
0.03 - 0.11
6 - 11
0.016 - 0.024
5 - 10
Notes: CFCs are identified by a numbering system developed by Du Pont. The first digit on the right refers to the number of fluorine atoms, the second digit refers to the number of hydrogen atoms plus one, and the third digit is the number of carbon atoms minus one (the zero is not written). Source: Environment Canada (1993b)
The Montreal Protocol, and its amendments in London and Copenhagen, have hastened the phase out of the release of ozone-depleting chemicals. Levels of CFCs will continue to rise, even if the chemicals are no longer released, because it takes up to several decades for them to reach the stratosphere where ozone destruction occurs.

The rates of build-up of ozone depleters have slowed since the implementation of the international protocols, but the reservoir of CFCs in the atmosphere will persist for several decades. Maximum ozone depletion is expected around the turn of the century, resulting in a further loss of ozone over Canada of 2% or 3%. The United Nations scientific assessment of ozone depletion for 1994 suggests that further measures (such as never releasing all halons in current fire extinguishing equipment, and collecting and destroying all existing CFCs) could lower chlorine loading by one-third over the next 50 critical years (UNEP 1995).


The construction, maintenance and use of roads result in airborne particles or dust larger in diameter than would be classified as particulate matter. Finer dust is discussed under particulate matter. Although dust is also produced naturally, road construction dust has been shown to significantly disturb residents within a 150 m strip of the construction site (Watkins 1980). Dust from unsealed roads can reduce agricultural productivity through photosynthetic yield loss, increased levels of pest, disease and weed incidence, dirty produce and poor pollination (McCrea 1987). Dust can soil and damage buildings and other structures and can also lower visibility (Watson and Jaksch 1978). Dust costs include increased cleaning and maintenance costs, reduced agricultural production and lower aesthetic qualities of the human environment. Environmental factors such as rainfall, shelter, wind, topography, ambient dust levels and road conditions are the main determinants of road dust impacts (McCrea 1987).

Other Toxic Pollutants

Airborne toxic pollutants emitted by internal combustion engines include benzene, methyl tertiarybutyl ether, polycyclic aromatic hydrocarbons (PAH), toluene, xylenes, aldehydes (primarily formaldehyde), and methylcyclopentadienyl manganese tricarbonyl, which is used as an octane-enhancing additive to gasoline. Each of these is suspected or proven to cause significant human health problems, including cancer, neurological disorders and damage to major organs. Some produce odours and may be responsible for much of the smell associated with traffic, particularly diesel vehicles. Aldehydes and PAHs are believed to be greenhouse gases.

Heavy metals are also harmful. Automobile exhaust is no longer a major source of lead pollution, since most gasoline in North America is now unleaded; however, lead that has been dispersed into the environment from gasoline combustion in the past continues to do harm to human health. Consequently, it should be accounted for as a by-product of transportation.

3.1.3 Air Pollution Damage

Primary and secondary pollutants have many possible negative impacts. Some pollutants have the greatest impact when they are concentrated, and so incur costs primarily in urban areas or next to a busy rural road. Topography and meteorological conditions strongly influence local concentration and impacts of these pollutants. The type and magnitude of impacts of other pollutants such as acid rain and ground-level ozone depend on where in a region they are deposited. Ozone-depleting substances and greenhouse gases have global impacts that incur the same cost no matter where they come from. Some pollutants produce a combination of impacts, incurring local, regional and global costs.

Roadside and local air pollution impacts take place in the area where the emission occurs. These impacts include human mortality (death) and morbidity (illness), reduced agricultural production, reduced visibility, corrosion of materials (buildings, rubber products, fabrics, plastics), increased cleaning costs and damage to the natural environment. Significant local air pollutants include CO, ozone, NOx, hydrocarbons, SOx, heavy metals, toxins, dust and particulates.

Leksell and Löfgren (1995) studied the dose of NOx, volatile organic compounds and particulates in Swedish urban areas. There are two types of doses, which add together: the first one, the "urban dose," reflects the general pollution level in the city; the second one, the "street dose," originates in the vehicle exhaust of traffic on the street. In large cities, the street dose amounts to about half of the urban dose, while in smaller towns, the street dose inhaled by people is a quarter, or smaller portion, of the urban dose. City centres are most hazardous. In the centre of Gothenburg, the simulations showed urban doses per unit mass of emissions several times higher than the average city-wide urban dose. The areas of high doses coincide with high population and pedestrian densities.

The impacts of significant air pollutants are summarized below.

Fine Particulate Matter Damage

The most damaging impacts of particulates are those on human health. Exposure to airborne particles can interfere with the normal functioning of the respiratory system and may cause heart problems and cancer. High mortality rates caused by particulates from transportation and industrial sources were not obvious until recently. The health damage mechanisms of particulate pollution were poorly understood, and smog and ozone were typically considered the main culprits in human health deterioration from air pollution. The health impacts of ground-level ozone, and the smog’s effects on visibility, cleaning costs and crops were emphasized by regional air quality management and many costing studies over the human health and mortality impacts of particulates.

In general, the smallest, inhalable particulates (labelled PM2.5 to indicate particulate matter smaller than 2.5µ) are the most hazardous to human health, causing respiratory irritation and possibly bronchitis (Halvorsen and Ruby 1981). A strong cause-and-effect relationship has been established between PM10 and human mortality from cardiovascular and respiratory disease among older people (Moffet and Miller 1993, Dockery et al. 1993, Vedal 1993, Dockery and Pope 1994, Seaton et al. 1995). Some particulates are toxic, carcinogenic or co-carcinogenic, especially if they carry an absorbed particle of a very harmful substance. These health effects, however, are not understood well enough to allow separation of specific damage from other air pollution damage to human health.

Larger particles, especially carbon, are believed responsible for most of the soiling in urban areas, and are the primary cause of visibility impairment from regional haze conditions (Ottinger et al. 1991). Soiling of the built environment, crops, skin and clothing with particles can be costly. Visibility is important to local residents for aesthetic reasons and, in areas that rely on tourism for income, for economic reasons as well. However, attribution of visibility losses to transportation emissions may be difficult. At coastal locations, the light-extinction contribution of human-caused sulphate aerosols may be overwhelmed by the ambient amount of sulphates generated by phytoplankton in the sea. Nitrate aerosols cannot be simply linked to human-generated NOx contribution because of the fairly complex interactions between aerosol constituents. Agriculture is likely a major contributor of nitrate precursors.

Global Warming

The threat of global warming (also called climate change or enhanced greenhouse effect) arises from the increasing concentrations in the atmosphere of gases that trap solar heat rather than letting it escape into space after reflecting from the surface of the earth. Aerosols arising from sulphur emissions from industrial sources, from combustion of fossil fuels and from burning of biomass have an offsetting cooling effect. Since the beginning of the industrial era, human activities have released greenhouse gases into the atmosphere at a much faster rate than the oceans and biosphere can absorb. As a result, the average temperature around the globe has risen by between 0.3° C and 0.6° C since the late 19th century; i.e., many times faster than has occurred naturally during earth’s climatic history. Human impacts may cause a climate change to occur in one or two centuries that would otherwise take thousands of years.

The first scientific assessment of the Intergovernmental Panel on Climate Change provided "best estimates" of 3° C average global surface temperature increase and 0.65 m mean sea level rise by 2100 (IPCC 1990). The second assessment (IPCC 1995) revised these estimates to about 2° C and 0.50 m, respectively. Considering likely range of scenarios for greenhouse gas and aerosol precursor emissions (based on assumptions about population and economic growth, land use, technology, energy availability and fuel mix in the period 1990-2100), the temperature increase could be between about 1° C and 3.5° C. Only 50-90% of the eventual equilibrium temperature changes would have been realized by 2100, and warming would continue beyond 2100, even if greenhouse gas concentrations were stabilized by that time. Sea level would rise 0.15 m to 0.95 m, and would continue to rise for centuries beyond the time of stabilization of global mean temperature.

Temperature changes of a few degrees on a global basis have been associated with dramatic changes in the regional patterns of precipitation. Animal and plant species migrated, adapted or became extinct over hundreds or thousands of years in response to such changes. Spruce trees, which now hug the Arctic rim as members of the boreal forests, girded the ice sheet that covered southern Canada, while oaks were displaced as far south as North Carolina. The difference in global average temperature between the last ice age and now is only 5°C.

Global warming and climatic changes could result in significant socioeconomic and environmental impacts (IPCC 1995a), including droughts and floods, reduced agricultural and forest production, desertification, species extinction and ecological system damage, coastal flooding due to sea-level rise, international conflicts over diminishing food and other resources, increased energy consumption for air-conditioning, extreme weather events, and loss of various environmental amenities. Projections of the direct costs of global warming range into several percent of global economic product annually for centuries to come. The economic sectors that are expected to experience the greatest negative impacts include water resources, agriculture, forestry, human health and urban infrastructure (Bein 1995). Because British Columbia is a coastal province and is economically reliant on the climate-sensitive resource and tourist industries, the impacts of climate change could be substantial. However, economically developed regions like B.C. would be better able to adapt to the change than developing economies.

Global warming is expected to continue even if emissions of greenhouse gases are stopped. CO2, methane, N2O and halocarbons have atmospheric lifetimes decades and centuries long. Climate scientists estimate that the present burden of greenhouse gases has already committed the earth to an estimated temperature increase of 0.5° C to 2° C, even if the atomospheric CO2 concentration is stabilized at today’s level. Studies of historical climate change conclude that nature could possibly tolerate the following limits of global warming without drastic changes to ecosystems (SEPA 1992):

The maximum rate of change is the limit that still allows ecosystems and species time to adapt. Temperature rises above the maximum increases might trigger rapid but unpredictable and non-linear responses that can lead to extensive damages to the ecosystems. The risks of serious ecosystem damages increase rapidly above the upper absolute value. Catastrophic surprises are probable (IPCC 1995; IPCC 1995a).

Although global climate change models do not have the resolution to predict the climate changes that would occur in regions the size of British Columbia, modellers agree on the types of changes in the Pacific Northwest. MacBean and Thomas (1991) believe that the region would experience a temperature rise similar to the average global temperature rise. A rise in sea level of 1 m could produce flooding along the coast of British Columbia, particularly the lower Fraser Valley and parts of the Vancouver Island coast. Precipitation could increase over most of the coast, but there is less consensus on this point (Cogan 1992). Any region may experience both positive and negative impacts, but local benefits are expected to be overshadowed by overall economic and environmental costs.

The threat is real and serious. A global warming of 2° to 5° C above the current level would bring the earth to a climate that has not prevailed for more than 120 thousand years. Application of the precautionary principle to global warming evaluations is, therefore, most appropriate.

Increased Ultraviolet Irradiation

CFCs and other halocarbons are implicated in the destruction of stratospheric ozone, the layer of gas that blocks harmful ultraviolet (UV) radiation from reaching the earth. The three categories of UV radiation are UV-A, the longest wavelength, UV-B in the middle, and UV-C, the shortest wavelength. UV-A is the least damaging form of UV and reaches the earth in greatest quantity, passing right through the ozone layer. UV-B radiation is potentially very harmful, but most of it is absorbed by the stratospheric ozone. UV-C is absorbed by oxygen and ozone in the atmosphere and never reaches the earth’s surface (Environment Canada 1993b).

Concerns about rising UV radiation levels are pronounced in Australia, New Zealand, South Africa, Argentina and Chile, the countries with the largest populations exposed to the consequences of ozone loss. Southern hemisphere experience in UV damage may indicate the future for the northern hemisphere (RSNZ 1993). The following is a summary of the harmful effects of UV-B. A more elaborate review, including interactions of ozone depletion with global warming and biogeochemical cycles, can be found in (Bein and Rintoul 1996a).

Increased exposure to UV radiation can cause skin cancer, eye damage, cataracts, immunological disorders and reduced crop yields. Current UV exposure rates result in skin cancer for one out of every seven Canadians, approximately 5% of which are potentially fatal melanoma; this rate could increase significantly because of ozone depletion. Present statistics do not yet reflect the long-term effects of UV radiation because skin cancer takes 10 to 20 years to develop. Other countries report similar results .

The effects of UV-B on humans also include eye damage, cataracts and weakening of the immune system. UV-B radiation can damage the eye lens, cornea, retina and the membrane covering the eye. "Snow blindness" is the result of overexposure. If repeated over the long term, snow blindness can cause permanent damage to the eye. Cataracts are a clouding of the eye’s lens and are a leading cause of permanent blindness. A sustained 10% thinning of the ozone layer is expected to result in nearly two million new cases of cataracts per year globally (Environment Canada 1993b).

The body’s immune system is its first line of defence against invading germs. Exposure to UV-B has been shown to increase the incidence and severity of infectious diseases and some cancers. A weakened immune system leaves the body susceptible to attack from parasites, bacteria, viruses and micro-organisms that are responsible for diseases ranging from cold sores to leprosy and malaria.

Excessive UV-B inhibits the growth processes of plants and may cause cancer in animals, but neither plants nor animals can protect themselves from the radiation. There is a high degree of variability in the response of different species to UV-B radiation. Domestic animals, both pets and livestock, develop skin cancers and eye damage under UV-B radiation. Tumours and infections from viruses, bacteria, fungi and protozoa are exacerbated in mice and guinea pigs under laboratory conditions. Skin lesions caused by sunlight have been reported in commercially reared fish.

Global ozone loss may lead to a loss of some species and consequently to serious effects since all life, is interconnected through the food web. UV-B radiation significantly affects the productivity of phytoplankton, the single-celled organisms that are at the base of freshwater and marine food webs, and are also agents in cloud formation, which is important for the climate regime. However, predicting the response of complex, interactive ecosystems from data gained on single life-form systems may lead to incorrect conclusions.

The economies of countries closest to the poles, including Canada, will be hardest hit by ozone depletion in the long term. Ground-level smog creation could increase with rising UV-B levels, affecting asthmatics and the elderly in urban areas. Water pollutants become fortified under UV-B. In addition to increased public health care costs, resource-based economies, dependent on the forestry, fisheries and farming sectors, could be affected by higher UV-B levels. Wood and plastics (including plastic paints and coatings) are degraded by exposure to UV radiation. All fibres, whether natural or synthetic, lose strength and colour under UV exposure indoors and outdoors. The economic impact of replacement and additional treatment necessary to protect building materials and fibres could be significant.

Wheat, rice, corn and soybean crops are expected to decline under the ozone depletion scenarios. Forestry, fruit and vegetable production could also be disrupted. Specific crops may be reduced by 5% to 7%. Since the process by which plants use nitrogen is disrupted by increased UV-B, soil productivity could seriously decline. Sensitive species of livestock will require protective shelters, and free-range livestock will require more land if plant productivity is reduced under increased UV-B.

Forestry and fisheries, the mainstay of British Columbia’s economy and already under stress from over-logging and over-fishing, could be further strained. If young, UV-sensitive tree species in clear-cut logged areas fail to thrive, the productivity of the forestry sector will decline. In water, industrial pollutants can become much more toxic and carcinogenic when exposed to UV rays. UV radiation can also trigger the formation of highly reactive chemicals that can kill organisms in fresh water. The cost of cleaning up polluted lakes and rivers could escalate as a result. Phytoplankton losses could disrupt the fresh and saltwater food chains and lead to a species shift in Canadian waters, reduction of biodiversity and reduced yields for commercial, sports and First Nations fisheries. Farmed fisheries in shallow ponds with no shade will have to reconstruct the facilities to better protect stock against UV radiation.

Out of concern for these environmental impacts, production of ozone-depleting substances and use are now limited by the Montreal Protocol, an international agreement on protection of the stratospheric ozone layer. Canada supported a 100% elimination of CFCs by January 1, 1996, possibly with some exemptions for essential uses. Measures have been taken to reduce CFC and other ozone-depleting emissions from all sources with the use of surrogate chemicals such as hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs). Atmospheric concentrations have levelled out as a result. However, these replacement chemicals also have negative environmental attributes (Beard 1992). For example, HCFCs are very strong greenhouse gases.

Although the rate of build-up of ozone depleters in the atmosphere has slowed as a result of the Montreal Protocol and its Amendments and Adjustments, problems still persist (UNEP 1995). Several countries with economies in transition will not comply in 1996. Some of them illegally export newly produced CFCs and halons to developed countries. CFC and other ozone-depleter manufacturers in the developed countries continue production for the developing countries, which are exempt from the international control meausres until early 21st century..

Acid Precipitation

SOx and NOx react in the atmosphere with water vapour to produce sulphuric and nitric acids. The acids then fall as acid rain, snow or mist (Mitchell 1991), resulting in damage to crops, forests and aquatic ecosystems, as well as human-made objects. Nitrogen and sulphur oxides can travel hundreds of kilometres before reacting with water vapour, so the impacts of acid precipitation transcend borders and affect areas and countries far distant from their origin.

The formation of acid precipitation depends on the volume of emissions released into the atmosphere, the climate and weather patterns carrying the pollutant, and the acid sensitivity of the receiving area. Motor vehicle emissions are the largest source of NOx and the second largest source of SOx emissions, after electrical utilities. Diesel vehicles burning high-sulphur fuel are the main transportation contributors. Improved SOx controls at utility plants are increasing the relative portion of motor vehicle SOx emissions. Low-sulphur diesel fuels can reduce the SOx emissions from diesel engines.

Acid precipitation due to transportation has not yet been proven to be a problem in the Pacific Northwest. It is believed that NOx has a fertilizing benefit to our forests and the acid is absorbed within the buffer capacity of the soils, so other ecosystems are not drastically affected. Nevertheless, if the amount of acid emissions increases with the growth in usage of motor vehicles powered by fossil fuels, the Pacific Northwest may start experiencing over-acidification and ecological damage regionally.

In coastal regions of British Columbia, sea salt in the air markedly influences sulphate ion concentrations, which must be adjusted in order to observe the effects of human-generated and other natural (for example, volcanic) sources. SENES (1992) describes earlier studies by others who measured the acid pollutants in precipitation in southwestern British Columbia. Elevated levels of sulphates were attributed in part to emissions from the ASARCO smelter near Tacoma, Washington. The studies also observed that concentrations decreased eastward of the Fraser Valley and that the influence of urban sources was clearly evident.

Secondary activities, such as vehicle manufacture and associated energy requirements in eastern North America contribute to acidification of those regions. Acidification has led to a significant reduction in biological diversity in tens of thousands of lakes in eastern Canada and northeastern United States (Ottinger et al. 1991). Acid precipitation has also been linked to a decline in hard- and softwood forests as well as agricultural productivity in these areas. Fifty-five percent of eastern Canada’s forests, which generate $14 billion worth of forest products, and 84% of the most productive agricultural land receive higher than acceptable levels of acid rain each year (Transport Canada and Environment Canada 1989). Acid precipitation can also erode many types of building materials including copper, granite, sandstone, marble and limestone (Ottinger et al. 1991). This corrosion can result in significant repair costs.

Acid deposition threatens human health by increasing the solubility of dangerous metals such as aluminum, cadmium, lead and mercury. These metals can leach from soils and lake sediments, contaminating drinking water and edible animal products. Acidic water can also dissolve toxic metals from water pipes, contributing to the contamination of domestic water supplies.

Ground-Level Ozone and Precursors

Ground-level ozone (a constituent of smog) is a local and regional air pollution problem. It results from photosynthetic reactions between volatile organic compounds, nitrogen oxides and oxygen. While ozone in the stratosphere protects organic life on earth by filtering ultraviolet radiation, it is harmful when present at ground level. Ozone is a potent respiratory tract irritant and there is good evidence that it produces appreciable respiratory morbidity in urban areas with high ozone concentrations. It is unlikely that ozone is responsible for eye irritation. Other constituents of photochemical smog (for example, peroxyacetyl nitrates) appear to be likely culprits (Copes 1995).

Ground-level ozone has also been linked to forest damage and reduced agricultural production (Adams et al. 1985; NRC 1991). Because volatile organic compounds and nitrogen oxides are both precursors of ozone, both are charged with ground-level ozone environmental costs. However, ozone development in some airsheds is primarily constrained by volatile organic compounds, and in others by NOx, so control strategies may vary depending on location.

The complexity of photochemical reactions between ozone precursors and the dependence of the reactions on meteorological conditions preclude a simple attribution of a fixed proportion of ozone and associated damage to each constituent pollutant. NOx are precursors of aerosols, which form part of fine particulate pollution, and NOx also cause acid precipitation. Studies in Sweden have found that the human health effects of NOx are governed by an almost linear relation between the average concentration of NOx and the number of persons troubled by the emissions (Leksell and Löfgren 1995). This dose-response relationship extends far below the regulated values of NOx concentration. Leksell and Löfgren attempted to attribute the pollutants to different consequences and damage costs, but because of the difficulties, they could provide only rough estimates. A better approach may be the assessment of total damage and redistribution to different vehicle types based on distance travelled and emission rates, a method adopted in a ministry study of fine particulate and ground-level ozone damages (SENES 1995; SENES 1994).

Other Toxic Pollutants

Undoubtedly, medical science has not yet identified and does not yet understand the risks to human health of all transportation-generated toxic substances. As an example, reports have appeared of high levels of radioactive polonium-210 in the air and in children’s teeth near major British freeways (Shared Vision Magazine 1995). The substance attaches itself to lead and migrates to the bone where it can irradiate the marrow. British officials are trying to decide whether to ban leaded gasoline, which has been linked to brain cancer, or unleaded gasoline, which contains the carcinogen benzene.

Another current issue in toxic pollution from traffic is the presence of strong detergent additives in unleaded fuels, which produce a host of harmful chemicals when burned in engines. The damage to health and ecosystems has not been assessed yet for these pollutants.

3.2 Noise and Vibrations Traffic noise is the transportation externality with perhaps the longest history of quantification. With the growth of the load capacity and number of heavy vehicles, concerns about vibration effects on humans and buildings arose, and the measurement methods developed for noise were found useful. However, the work to date has concentrated on the effects of noise and vibrations on humans, and not much is known about the impacts on wildlife.

3.2.1 Traffic Noise

Noise is unwanted sound. It is rapidly increasing worldwide, and both changes in noise sources and their growth contribute to the worsening situation. Road traffic is one of the most frequent non-occupational sources of noise exposure, together with construction, aircraft operations and rail traffic. About half of the population of the United States is exposed to unacceptable traffic noise (Talbott 1994).

Road construction and vehicle operation cause a variety of noises. Noise originates from engines, tire-road contact and braking, emergency vehicle sirens, vehicle doors and trunks opening and closing, and vehicle radios and horns. Traffic noise is unpleasant and distracting, and can be disturbing to sleep and other activities. It degrades the comfort and well-being of people outdoors and indoors. Consequently, consumers perceive the values of real estate located in noisy environments to be lower than in a quieter environment. Traffic noise can also disturb wildlife.

Noise is typically characterized by the intensity, frequency, periodicity (continuous or intermittent) and duration (acute or chronic) of sound. Noise is measured in decibels (dB) on a logarithmic scale. A 10 dB increase represents a doubling in noise level. Decibels A-weighted (dB(A)) emphasize the frequency sensitivities of human hearing and correlate well with subjective impressions of loudness. Common noise levels are: whisper, 30 dB(A); normal conversation, 50 to 65 dB(A); inside a car with a loud engine, 70 dB(A); average city traffic noise, 80 dB(A); diesel truck, (64 km/h at 15 m distance) 84 dB(A); lawnmower, 85 to 90 dB(A); symphony orchestra or chain saw, 110 dB(A); shotgun firing, 130 dB(A).

According to a 1990 OECD report, "Transport is by far the major source of noise, ahead of building or industry, with road traffic the chief offender." At low speeds, most noise comes from the vehicle engine and drive train; at higher speeds, aerodynamic and tire-road noise dominate (Homberger et al. 1992). Overall traffic noise increases, albeit not proportionally, with speed, traffic volume and percentage of large trucks and motorcycles in the traffic stream.

Noise depends more on the types of vehicles and the type of operation than on traffic volume. Large trucks and buses, which have much larger engines and tires, generate disproportionately more noise per vehicle-km than light vehicles. Traffic running at a uniform speed generates less noise than the same traffic under stop-and-go or fluctuating speed conditions. Stopping and speed fluctuations cause increased noise emissions from vehicle engines and brake noise. Engine noise is also higher in driving uphill, compared with driving a level road at the same speed. Vehicle parking noise has the additional components from the closing of doors and trunks.

Studies have indicated that noise can affect social, behavioural, mental and physical health, but the mechanisms for this wide array of effects are not yet fully understood despite considerable research. The adverse effects of noise on an individual can be cumulative with repeated or prolonged exposures, especially where there are no rest periods from the noise. The most frequently studied physiological responses to noise are high blood pressure and cardiovascular disease. An increase in the risk of cardiovascular disease of only 10% can be important because of the large number of people exposed to noise (Thompson 1994).

The most commonly recognized effect on people in the community is annoyance, which impairs the quality of life of those affected (Thompson 1994). Rylander et al (1986) found that an increase of the number of heavy vehicles from 1,000 to more than 3,000 per 24 hours did not increase the extent of annoyance. The highest noise level from single vehicles rather than the number of events above a certain limit, determines the extent of annoyance.

The impact of noise generated by traffic depends on the receptor characteristics. Noise energy decays with distance, hence only those people located in the immediate vicinity of a travelled road receive a high dose of noise. In remote and rural areas, however, where the background noise level is lower, even one vehicle’s noise is noticeable, sometimes at a great distance, depending on topography, meteorological conditions and attenuation by tree and plant cover. Urban greenspace, which is intended for recreation and relaxation, is increasingly affected by noise from increasing traffic. New transportation corridors in these areas often cut through or run at the edge, severely reducing or destroying the amenity of peace and quiet.

Traffic noise at night, particularly if it is intermittent, causes sleep disturbance. During the day, it leads to tiredness, irritation and stress, which may be reflected in a loss of productivity, higher accident propensity and more frequent errors. Traffic noise is also a frequent cause of interference in verbal communications and a disturbance to quiet activities and relaxation, especially outdoors. Exposed for a longer time, humans might be affected by noise mentally (Thompson 1994).

The road traffic noise nuisance is overwhelming compared with the noise generated by the other transportation modes. Even in a country like Germany, which has significant noise levels from heavy rail and aviation, road traffic noise abatement takes a 70% share of the total transportation noise countermeasures (Weinberger 1992). The share wouldbe much higher in British Columbia, owing to smaller, by comparison, air and rail traffic volumes.

3.2.2 Traffic-Induced Vibrations

Traffic vibration is a common source of disturbance affecting people, some buildings and sensitive equipment. Passing vehicles can induce vibrations in buildings through both airborne and ground-borne vibrations. Airborne low-frequency sound (50 to 100 Hz) produced by large vehicle engines can excite the resonant frequencies of rooms by acoustic coupling through windows and doors. This may produce detectable vibrations in building elements, particularly if they are light and flexible. High levels of vibration can be measured on window panes facing heavily trafficked roads. This may produce annoying rattles. While at the most exposed locations acoustically induced floor vibrations can become perceptible, vibration levels in the hard structure of the building are much lower.

Ground-borne vibration has a dominant frequency typically in the 8 to 20 Hz band and is produced by the varying forces between vehicle tire and road irregularities. The propagation of these vibrations depends on vehicle and load characteristics, vehicle speed, road unevenness and ground conditions. Soft soils such as alluvium and peat moss induce the largest response of foundations to ground-borne vibrations. The hard structure of a building is affected more than by the airborne vibration, since this vibration enters the structure through the foundation. The ground-borne vibration is felt most at the upper levels of a building.

It has been known for a long time that human response to vibration is both physiological and psychological (Chilton et al. 1973). Humans often classify vibration as unacceptable at levels lower than those that cause structural damage. Watts (1990) summarized international findings on the subject and also carried out vibration tests on buildings. Overall fewer people are bothered by vibrations from traffic than by traffic noise, but the fraction of residents seriously bothered by vibration (8%) is similar to the percentage seriously bothered by noise (9%). Where vibration nuisance is caused mainly by airborne vibration, it is the low-frequency content of the noise that causes the problem. Standard acoustic indices are generally better predictors of disturbance than are measures of window vibration, traffic flow or road roughness. A composite index of heavy vehicle flow and distance of the affected building from the road is as good a predictor.

Ground-borne vibration affects only a small proportion of residents. Nuisances and anxieties about building damage are likely to arise where the-ground is soft. Sensitive equipment and critical work areas can be affected by very low levels of vibration close to the level of perception. There is no evidence that traffic vibration can also cause significant damage to buildings, but a small amount of superficial damage could be produced by sustained exposure to very high levels of ground-borne vibration. However, it is unlikely that such exposure would be tolerated by the occupants for a longer period (Watts 1990).

3.3 Land Use Impacts Land use changes caused by transportation create a wealth of social and economic benefits, but they impose environmental and social liabilities at the same time. In general, the benefits tend to be captured by transportation users and land owners, while society as a whole bears many of the costs. Urban sprawl is a good example of a land use change that provides benefits to the user but imposes environmental and other external costs on society. In addition to its costs to ecosystems and farmlands, urban sprawl creates the social costs of less neighbourhood interaction and more automobile dependency, traffic congestion and noise, and air quality deterioration. It is therefore important to include the disbenefits of land use change in the policy and planning evaluation processes.

Social costs induced by land use changes are outside the scope of this report. The shadow prices of environmental damages arising from land use changes caused by transportation are the result of a complex chain of causes and effects.

3.3.1 From Land Use Impacts to Environmental Damage Costs

To define or measure the external environmental losses associated with transportation projects, it is necessary first to understand the affected environmental benefits that existed before a project was undertaken.

Greenspace Benefits

Wetlands, forests, farmlands, parks and other biologically active lands, are collectively called greenspace or open space by land use planners. The term greenspace is often used with reference to urban open spaces; here, it refers to biologically active lands in general. Greenspace provides various external benefits (Alig 1983, Dixon and Sherman 1991, SFU 1990, Knapp and Nelson 1992), which are listed in Table 3.11. These external benefits exist in addition to benefits to the land owner, and are not reflected in the land’s market value because they are enjoyed by society as a whole and by the environment. The benefits in Table 3.11 include non-use values as well as use values, which in turn include consumptive and non-consumptive uses.

Land-use environmental costs can be defined as the losses of external environmental benefits provided by land in its undisturbed use. Much of the province’s land area has already been "disturbed" to a greater or lesser degree by human activity, and some has been completely altered from one type of use to another, for example, by change from floodlands to agriculture. For practical reasons, the baseline of environmental benefits lost must begin from the current use, rather than from the original, pristine ecosystem.

Table 3.11 Greenspace External Environmental Benefits
Benefits to the Environment
Benefits to Society
  • Ecological life-support processes
Circulating and cleansing air and water Nutrient fixing and cycling

Soil formation and maintenance

  • Biodiversity
Species protection (habitat)

Ecosystem diversity

Evolutionary processes

  • Watershed protection
Erosion control

Flood reduction

Regulation of stream flows

  • Recreation and tourism
  • Community/cultural identity
  • Education and research
  • Consumptive benefits
Resource production
  • Non-use benefits




  • Future values


Each area of land used in a certain manner provides a bundle of external environmental benefits, which are interdependent and interactive, often in very complex ways. However, the separated qualities, such as hydrologic flows or the value of fish habitat, are sometimes more readily assessed. Human transportation and non-transportation activities undertaken on or in proximity to a land parcel can affect greenspace benefits. A loss of benefits constitutes a loss to society and to the biosphere, both locally and globally. Human activity can also enhance external environmental benefits of an existing land use. When a number of different activities are taking place, it is frequently difficult to assign the observed results to specific causes or activities.   Types of Transportation Impacts on Land Use

All transportation activities cause impacts by changing current land use patterns. The degree of impact can range from a minor reduction in only a few of the environmental benefits, to a total alteration or destruction of the ecosystem. Impacts of a transportation project can be direct, indirect and cumulative. Direct impacts usually occur at the same time and place as the project, and are discernible at the design stage, whereas indirect impacts on land use are usually more widespread or delayed, and involve intermediary actions. As stated in Beale (1993), "A project induces development or changes in land use, and these changes have environmental impacts. These induced changes are the indirect effects." Cumulative impacts include the direct and indirect, as well as impacts from other causes.

The direct impacts of a transportation project are the conversion of land for use as roadways and immediate supporting infrastructure, such as rest areas and highway buffers. In particular, paving an area effectively reduces its environmental benefits to zero. The indirect impacts can be due to both the proximity of the road and the existence of the road. Proximity impacts include habitat severance, habitat degradation, air and water pollution, changes in drainage patterns, strip developments along roadway, aesthetic blight and increased noise. Existence impacts, often caused by improved access, may include increased industrial activity, hunting and recreational usage, or urban sprawl and urban shadow. Urban sprawl is low density land development at the urban fringe (semi-rural area outside the suburbs). Urban shadow is the transition area between the fringe and the thoroughly rural area (Gertler and Crowley 1977). (See Section 3.3.4.)

According to a NCHRP research project cited by Beale (1993), a cumulative impact is "the influence on the environment which results from the incremental impact of the action when added to other past, present and reasonably foreseeable future actions regardless of what agency…or person undertakes such other action." Even though some of the cumulative impacts may seem independent of the transportation project, it is often necessary to properly identify and assess them as part of the total land use impacts of transportation. For example, if a transportation project speeds up growth that would have occurred, but would have taken longer without it, the short-run acceleration is an indirect impact, even though the long-run growth is a cumulative, exogenous effect.

Determination of Damage to Greenspace

In general, different degrees of damage can result from a similar impact on the greenspace. Some species have narrow ecological niches, and a small change in ambient water temperature, or supply of a certain plant or nesting area, will have large effects on their population; others are more robust and adaptable. How much damage is done depends on the ecosystem characteristics of the piece of land in question. Determination of the damages can be aided by an understanding of the dose-response functions. Assessment of damages caused by land use changes is challenging because of multiple and cascading impacts, hard-to-measure damages, and the significance of critical loads and thresholds that are not sufficiently understood.

A land use change involves not a single response to a single impact, but possibly a very large set of responses to a set of impacts. Each component change may involve losses to a complex set of environmental processes and products, depending on a complex web of relationships. Clearing a patch in a forest for pasture land changes sunlight, soil qualities, ground cover composition and other factors, each of which (alone and synergistically) affects the set of environmental benefits available from the cleared patch and from the surrounding forest. The dose-response function for a particular change may be entirely specific to that location, and no truly general functions may apply.

Dose-response functions should ideally consider the relationship between direct and indirect greenspace changes. A kilometre of road will directly affect a certain number of hectares of land, and will also indirectly degrade the habitat and bioproductivity of a certain area. It will also indirectly induce more or less sprawl and other effects, depending on location and other factors. Many land use changes not only give rise to immediate damages, but themselves may induce further changes, which then create damages. Such cascading indirect impacts, which interact with other cumulative changes, are even harder to define and measure. In evaluations, diverse and complex ecological relationships are generally aggregated into relatively few essential characteristics or attributes. Empirical studies are lacking on the effects of such abstraction on the value of information given to policy makers (Alig 1983).

A final set of issues concerns scale, critical thresholds and irreversibility. There exists generally a minimum size or a maximum level of disturbance for a given ecosystem that allows it to remain viable. Below the critical size or beyond the critical load, the ecosystem will not be able to reproduce and maintain itself. This fact is often represented in terms of habitat requirements for particular species, and is also true of biotic communities. The thresholds are "fuzzy" because a given ecosystem may be sustainable in simplified form even if certain component species or processes are degraded or missing. The thresholds must be understood in order to assess possible damages from a change in land use.

The critical threshold between viability and nonviability varies considerably among ecosystems. Humans may unknowingly force an ecosystem or species over its threshold, since damages are often cumulative and lag behind impacts. By the time the effects are noticed, it may be too late to reverse them. Species extinction is the most obvious example.

Land use impacts are often irreversible and the principle of a minimum viable scale with respect to the size of a land parcel is usually violated. What humans see as "the last precious hectare" of a wetland, for example, may in fact have already been reduced below the threshold size necessary for sustainable functioning. Its loss would entail cultural, social, aesthetic and other non-economic losses to humans, since the patch of wetland can no longer maintain itself naturally at a sustainable level. Both the size and the number of parcels of land of a certain ecological type are important. Even if the total area is sufficiently large, its fragmentation can cause significant environmental damages. The fragmentation of Vancouver Island marmot habitat is an example. Conversely, loss or degradation of even a small area, if no other areas are available, can cause losses, for example staging areas for migratory waterfowl.

Some losses of external environmental benefits are especially hard to define and perhaps unmeasurable. Benefits, such as spiritual and aesthetic, exist in the relationship between the world and human perceptions. Many environmental benefits of greenspace are non-consumptive and non-use. Bequest and existence values in land use change appraisals can be substantial. Once the damages are defined and measured, they can, in theory, be valued. This process is also subject to many difficulties, which will be described in Chapter 4.

3.3.2 A Simplified Method for Assessing External Environmental Benefits

Every piece of land has a unique bundle of external environmental benefits that are cumbersome to assess. We propose to simplify by (1) aggregating the environmental benefits into a finite set of land use types, and (2) making the assumption that each land use type has an average set of environmental benefits per hectare. This approach abstracts from the many differences between different cases of the same type—for example, between one wetland and another—and assigns an average set of benefits to each hectare of that type. For policy analysis and higher-level planning, this may be a necessary and feasible simplification. For a specific project, it is best to examine the specific characteristics of the greenspace in question.

For the proposed analysis, land uses are divided into the following categories:

Benefits are often highly correlated. A land parcel with high bioproductivity is likely to be high in biodiversity, visual appeal and other benefits, even though the correlations are by no means one-to-one. As Rolston (1985) put it, "The commensurability of values is…a pseudoproblem, because these nonconsumptive values reinforce and need not be traded off against each other." To account for the entire pool of benefits may not be possible, but because of this correlation among benefits it may be less necessary.

The external environmental value of land varies considerably between the land use categories. Based on our review of the literature, the level of various external benefits found in each of the land use categories is identified in Table 3.12 as high, medium or low. The external benefits are divided into air and water quality, ecological, flood control, recreational, aesthetic, cultural and economic, as defined under Table 3.12.

While various human activities affect land use, only losses of environmental benefits from road transportation activities are assessed in this report. Our simplified approach construes the reduction as a change in land use type, for example from second-growth forest to pavement. This approach defines a relatively clear base for comparisons. The "before" case is a type of land use with an assigned benefit set, as is the "after" case, and the loss of benefits can be inferred by taking the difference between them.

3.3.3 Impacts of Roads and Traffic on Land Use

It has been widely recognized that roads, motor vehicle traffic and urban development incur environmental costs through their effects on land use patterns (Beard 1992, MELP and Environment Canada 1993, CORE 1994, Miller and Moffet 1993, Works Consultancy 1993, US DOT 1993, Hanson 1992). OECD (1994) stated: "The main ecological impacts of road projects are due to losses of natural features, changes in hydrology, habitat loss and fragmentation, severance effects and the specific conditions of roadside habitats, including introduced foreign plants through landscaping." These and other impacts are summarized in Table 3.13.

Table 3.12 External Environmental Benefits of Land Uses
Land Use
Air Quality
Water Quality
Flood Control
Wetlands High High High High High High High High
Pristine Wild lands High High High Varies High High High Variese
Urban Greenspace High High Medium Medium High High High Variese
Second Growth Forest High High Medium High High Varies Medium Medium
Farmland Medium Medium Low Medium Low Varies Medium Varies
Pasture/ Range Low Medium Low Low Low Varies Medium Low
Mixed Urban Low Low Low Low Varies Varies Varies High
Highway Buffer Low Highf Low Low Low Low Low Noneg
Pavement None None None None None None None Noneg
a. Including wildlife habitat, species preservation and support for ecological systems.

b. Recreation includes hunting, fishing, wildlife viewing, hiking, horse riding, bicycling, etc.

c. Cultural benefits include preservation of culturally significant sites, harvesting traditional resources and support for traditional activities.

d. External economic environmental benefits are the economic benefits of a piece of land enjoyed by people who do not own the land. This includes the economic benefits to a community of tourism, fishing, wild plants and animals, and agriculture.

e. The economic value of wetlands, forests and urban greenspace is reflected in tourism and recreational expenditures, increased adjacent property values, water resources quality and availability, and fisheries.

f. British Columbia’s highway buffer management practices (minimal herbicide use, natural development) optimize water quality benefits. Benefits may be lower in other jurisdictions.

g. Highway buffers and pavement provide social benefits, but no environmental benefits.

Environmental regulations, pollution control equipment and mitigation efforts may reduce the environmental damages, but generally do not eliminate them, since there are usually residual costs inherent in road development and use. The environmental and social costs of road construction on land use are durable and often irreversible. Once a wetland is drained, an old growth woodland logged and paved, an opportunistic non-native species introduced, or an urban development established, some of the land’s original ecological, aesthetic and social benefits are lost forever. Mitigation, replacement or repair of ecosystems is slow, expensive and often ineffective.

Greenspace impacts impose a number of environmental damages:

Table 3.13 Roadway Environmental Impacts
Direct Impacts
Indirect Impacts
  • Land paved for roads
  • Clearing along roadways for visibility and safety buffers
  • Land cleared or modified by roadway support facilities
  • Rivers, streams and shorelines affected by roads and bridges
  • Road kills and injuries
  • Thermal effects of paved surfaces
  • Development, especially urban expansion
  • Parking facility construction
  • Wildlife disturbed by noise, pollution and human activity
  • Trash
  • Introduction of non-native species
  • Increased land use conflictsa
  • Planning blightb
  • Notes: a. Land use conflicts typically involve complaints by new residents about agricultural activities. b. Planning blight refers to the tendency of land owners to defer maintenance and improvements on land whose status is uncertain because of extended planning processes.
    Because of the environmental impacts of roads, wilderness areas are usually defined by the fact that they are roadless (Ambio 1989; Foreman and Wolke 1992). Roads are specifically not recommended in preservation and wilderness areas in British Columbia (RTEE 1993). They occupy four percent of the province’s total area (RTEE 1994).

    The area of direct environmental impacts for a four-lane highway can be calculated based on Table 3.14, which shows the lower bound on the land requirement of a typical highway. The land-area requirements for roads are higher in rolling and mountain terrain. The total area affected by environmental impacts (including noise, disruptions to surface and sub-surface drainage of wild and semi-wild habitats, introduced development, introduced species and visual intrusion) is normally much larger than the direct impact, and is affected by factors such as traffic volumes, land use patterns and ecological sensitivity.

    Indirect impacts are often significant and may represent greater total land use impacts than direct impacts. The impact of a single land use change may be small, but it may contribute toward an overall trend that, in total, incurs significant costs. Indirect and cumulative impacts can be especially large if a project, such as a road capacity improvement, eliminates existing constraints to growth. In this case, it can increase the speed and scale of development, causing significant indirect and cumulative land use impacts. Cost analysis should be broad enough to include these impacts (Beale 1993).

    Indirect impacts can be determined by comparing the situations with and without a project or policy (van Kooten 1993). This approach is especially important because land use controls are seldom completely effective (Knaap and Nelson 1992). If latent demand exists for development in an area, improved road access is almost certain to increase development and reduce external environmental benefits even if land use management strategies are implemented.

    Table 3.14 Four-Lane Highway Direct Land Requirements
    Width (metres)
    Land Used (m2/km)
    Road 14.0 14 000
    Shoulder 9.5 9 500
    Buffer 22.0 22 000
    Total 45.5 45 500
    Source: Statistics Canada (1991)
    Table 3.15 Space Requirements of Transportation
    Bicycle Work (m2/9 hours) 13.5 7.5 21
    and Motorcycle Leisure (m2/3 hours) 4.5 7.5 12
      Shopping (m2/1.5 hours) 2.5 7.5 10
    Automobile Work (m2/9 hours) 68 17 85
    (1.33 passengers) Leisure (m2/3 hours) 23 17 40
      Shopping (m2/1.5 hours) 11 17 28
    Bus (daily average: Normal Roads (m2/hour) 0 7.5 7.5
    20 passengers) Bus Lane (m2/hour) 0 30 30
    Bus (peak period: Normal Roads (m2/hour) 0 2 2
    80 passengers) Bus Lane (m2/hour) 0 7.5 7.5
    The amount of road space required per passenger-kilometre varies significantly by mode. In terms of space occupied by the vehicle on the road, cars can move only a small fraction of the passengers moved by the more efficient modes, including bicycling and walking (Lowe 1989). Table 3.15 indicates road and parking space requirements of passenger vehicles in various occupancy and usage situations. Automobile use is a much greater contributor to road-space demand than other modes. Source: Quinet (1994)
    Indirect impacts can also occur without a specific project. For example, if a road improvement is not made, some of the sprawl that is avoided in that location may be transferred to other areas if regional development is not managed in a comprehensive manner. Similarly, if motor vehicle use is reduced, consumers may spend the time and money they save in ways that also have external environmental and social costs, although overall these are probably small compared with the externalities of vehicles. We currently have no way to account for the difference between gross and net external cost savings, but the existence of such secondary impacts is acknowledged.

    Habitat loss is the single most important factor affecting wildlife populations in the province, and urban development, highways and roads are responsible for major habitat losses (MELP and Environment Canada 1993). Because a particular forest, wetland or stream can provide habitat to many different species, degradation of these lands incurs both market and nonmarket costs. Currently the greatest habitat loss occurs through direct use, fragmentation or insularization. Transportation, either through road building or urban sprawl, has been recognized as a major cause of habitat loss and a threat to biodiversity. Three of the five management categories within the provincial Protected Areas Strategy do not permit roads or highways (Province of British Columbia 1993). Section 3.8 discusses the effects of land use change on biodiversity.

    Habitat can be lost directly through the construction of road rights-of-way and indirectly through the modification of drainage or other elements of the physical environment. However, the fragmentation of large tracts of continuous land and the provision of access to previously inaccessible areas by roads or highways are likely greater causes of habitat reduction. A study of deforestation in the Brazilian Amazon basin between 1978 and 1988 found that only 38% of the habitat affected could be attributed to outright forest conversion (Skole and Tucker 1993). The remainder was the result of fragmentation. The western forest of Ecuador was largely undisturbed until after 1960 when a newly constructed road network led to the swift incursion of settlers and clear-cutting of most of the area. In British Columbia, road access to previously inaccessible areas can lead to increased mortality of game species through hunting and poaching. Conversely, road rights-of-way have been noted as providing valuable nesting and forage for certain bird species.

    3.3.4 Urban Sprawl

    Urban sprawl, is one of the indirect environmental costs associated with road construction. Yeates (1975) found that the average urban land consumption rate for the Windsor to Quebec City region was 56 hectares per 1000 people in 1971 and that the trend was towards an increasing rate to about 65 hectares per 1000 people in the year 2001. At these consumption rates, the addition of an estimated 11 million people in the region between late 1970s and the end of the century would require 0.67 million hectares of land.

    This area would be equivalent to a 2-km wide strip along the Canada-United States border; that is, not much in terms of the total area of the country. However, the urban growth tends to absorb the most ecologically, agriculturally and recreationally valuable land, particularly in Quebec, Ontario and British Columbia—the provinces that are the most heavily urbanized and where people in cities press on limited regional farm land of good quality. In addition to farmland, there are recreational lands, water supply and recharge areas, and sand and gravel deposits critical because of the tight constraints of haulage costs. Gertler and Crowley (1977) pointed out that the "competition for land accelerates the thrust" into the urban field and that the indirect urban intrusion effects, such as the promotion and speculative holding of rural land for urban purposes, consume as much rural land as the urban built-up area itself.

    The development of roads and other facilities in an existing urbanized area may impose little environmental cost because the land provides little environmental benefit. The same development on existing greenspace may significantly reduce environmental amenities. By reducing density and developing land that is currently greenspace, urban sprawl represents an increase in per capita appropriation of land transformed from an original habitat or use. In British Columbia, sprawl poses a threat to valuable resource lands, particularly forests on Vancouver Island and in the Lower Mainland, and agricultural lands in the Fraser Valley, the Okanagan and the Saanich Peninsula (CORE 1994).

    Urbanization tends to occur in areas that have high environmental value, such as fertile valleys and shorelines. Despite Canada’s enormous size, only about 5% of its total area has high agricultural potential, and it is in these areas that most cities and towns are located. Only about 10% of British Columbia is considered suitable for human settlement (Moore 1990), and these are the same lands that provide agricultural and unique wildlife habitats. Between 1980 and 1987, 4 354 ha of rural land (mostly farmland and wildlife habitats) were converted to urban uses in the Fraser Valley (MELP 1993).

    The environmental costs of urban sprawl have been broadly recognized in recent years by all levels of government. The Capital Regional District Roundtable on the Environment (CORE 1994), the British Columbia Commission on Resources and Environment (CORE 1994), the British Columbia Round Table on the Environment and the Economy (RTEE 1993) and the current transportation plan for the Greater Vancouver region all urge action to discourage, control and manage urban sprawl. VHB Research & Consulting (1992) describes urban sprawl as one of three primary environmental costs associated with current land transportation in all of Canada.

    The Canada Mortgage and Housing Corporation (Isin 1993) points out that, apart from direct environmental problems associated with sprawled land use, such as consumption of farm land and more automobile emissions, the low density urban form competes with energy-efficient transportation, efficient infrastructure and compact urban form.

    Urban sprawl represents a major threat to both humans and the environment. Roley (1993) states, "The net effect on wildlife of automobile-dependent urban sprawl is the fragmentation of habitat and the isolation of these fragments and their wildlife populations from one another...The automobile, in other words, has become the greatest predator of wildlife." Urban sprawl can also have significant impacts on farm and forest lands that are not actually developed through the urban shadow effect. As land nearby is developed, land values and tax assessments on the urban fringe increase. Speculation, land use conflicts and changing social standards can discourage agriculture near urban areas, and deter long-term planning and investment to improve farms (Nelson 1988). Even a small amount of direct development can have a major indirect impact on agricultural production as land owners anticipate continued urbanization (Pond and Yeates 1993).

    Road improvements encourage urban sprawl. Hanson (1992) acknowledges various factors that contribute to urban sprawl, including policies to subsidize single family housing, low rural land prices, telecommunications and personal preferences, and states, "An essential element in the evolution of dispersed land use patterns has been the emergence of the the dominant mode of personal transportation and the provision of highway infrastructure to accommodate automobile travel." Section 3.4.1 discusses the correlation between land use density and total in-home and transportation energy use.

    Emphasizing the role of roads in contributing to environmental impacts directly and by encouraging urban sprawl, the British Columbia Ministry of Environment, Lands and Parks and Environment Canada state, "Direct impacts of construction [of roads], such as damage to streams, are largely controlled through a variety of guidelines. It is more difficult to control indirect impacts, such as interruption of habitat continuity and the disturbance or hunting of wildlife. Good road access to an area often leads to further development. This means that both the positive and negative impacts of roads tend to increase with time." (MELP and Environment Canada 1993).

    CORE (1994) establishes a land use goal of developing a transportation system that "avoids transportation projects which encourage or subsidize inappropriate land development" such as development of particularly valuable resource lands, environmentally sensitive areas or areas where population growth is inappropriate. A Transport 2021 report from the Greater Vancouver Regional District (1993b) states "transportation investment is believed to influence land use by directing growth to areas which become more accessible via the new transport links. Transport shapes land use by selectively providing access [original emphasis]: good access to some areas but not to others."

    3.4 Resource Consumption Road construction and maintenance, motor vehicle manufacture, and operation of vehicles consume significant amounts of resources, including petroleum and associated products (gasoline, diesel fuel, lubricants, bitumen, etc.), metals; electricity, aggregates (sand, gravel, crushed rock), plastics, glass and rubber. The extraction, processing and distribution of these resources impose a variety of environmental impacts and associated costs ranging from harmful emissions into air, water and soil, to a reduction in nonrenewable resource stock.

    Resource consumption also incurs social and economic costs. Reliance on petroleum imports, for example, involves costs of direct subsidies, macroeconomic impacts of oil import dependence, and the cost of energy security. As these costs are not strictly environmental, they are not considered within this report. Alternative transportation fuels—including synthetic fuels from biomass, coal or electricity—will not be explored either, since they currently account for only a small portion of total energy used by land transport. However, if the future use of these fuel sources should increase, their environmental impacts must be accounted for.

    The most cost-effective way of reducing the impacts of resource consumption is to consume less. This does not necessarily mean negative economic impacts. Resource savings can be achieved through closing the production-consumption and disposal cycles, and through more efficient use of resources. Transportation efficiency is achieved through switching to non-motorized and mass transit modes, as well as engine efficiency improvements. Ensuring that vehicles and infrastructure are durable, thus lengthening their life cycles, will also reduce resource consumption.

    3.4.1 Energy Consumption

    Energy consumption by humans greatly affects the biosphere. Energy is currently generated mainly by combustion of fossil fuels, which create local, regional and global atmospheric problems. Energy consumption is an indicator of the total resource consumption of a nation or region because fossil fuels are required to provide energy for human activities and for the production and consumption of goods and services. Energy is consumed directly in the activities of transport and indirectly during associated activities such as provision of vehicles and fuels.

    Direct Consumption

    Petroleum products are the resources most commonly identified with motor vehicle use. In 1990, transportation accounted for 29% of Canada’s end-use energy demand (Environment Canada 1993). In North America, transportation accounts for over 60% of all petroleum used, representing about 25% of all energy consumed. Nearly 75% of transportation petroleum is used by road vehicles, with the remainder being consumed by air, water, rail, pipeline and off-road transport. In total, North American road vehicles consume over half of the world’s automotive fuel supply. Through a combination of geography, climate and consumption habits, Canada’s per capita automobile ownership, mileage and total energy use are among the highest in the world. The average Canadian car uses more than 11 000 L of fuel before it is scrapped. By comparison, a 5-axle truck running 160 000 km per year uses about 100 000 L of diesel fuel annually, while a 2-axle truck engaged in urban distribution service and covering 40 000 km per year uses about 15 000 L of diesel fuel or 20 000 L of gasoline annually.

    In 1992, Canadian sales of taxable fuel for road vehicles reached 31.8 billion litres of gasoline and 8.46 billion litres of diesel. In B. C., the sales reached 3.67 billion litres and 0.94 billion litres, respectively (Statistics Canada 1993).

    Upstream Consumption

    Aside from the fossil fuels used to propel motor vehicles, energy is used to produce and distribute fuels, and to produce and maintain motor vehicles. Collectively called upstream energy, it is significant when compared with the energy consumed during vehicle driving. This energy must be accounted for as it comprises a large percentage of the total energy necessary for the motor vehicle production-use-disposal cycle.

    Automobile materials processing and assembly consume the energy equivalent of 1500 L of oil (Warner and Glenys 1991). This is one-seventh of the energy typically used to operate the vehicle during its lifetime. The total flow of energy, direct and indirect, in the manufacturing process is termed the embodied energy. For example, the energy embodied in an automobile includes the energy consumed directly in the manufacturing plant plus all the energy consumed indirectly to produce the other inputs, such as glass, steel, labour, capital and the plant itself. Little vehicle manufacturing is located in British Columbia. However, the threats and costs of environmental damages associated with energy used for auto production must be considered the responsibility of all automobile consumers, no matter where production takes place.

    Table 3.16 Energy Used for Upstream Vehicle and Fuel Activities
    Vehicle Production Materials

    103 MJ

    Vehicle Assembly

    103 MJ

    Transport, Retail, 


    103 MJ

    Fuel Production

    103 MJ

    Total Upstream Energy

    103 MJ

    Passenger car 53.3 14.2 66 138 273
    Passenger van 65.5 17.4 98 213 394
    Light 2-axle 185.5 49.3 194 257 686
    Heavy 2-axle 299 79.4 1 121 1 172 2 672
    5-axle 589 157 2 963 4 765 8 474
    8-axle 873 232 2 963 6 179 10 840
    Transit bus 524 139 1 321 3 436 5 419
    Articulated bus 781 208 1 993 4 810 7 793
    Note: MJ = megajoules. Energy values given represent the equivalent electrical energy required, not the total energy required to produce that electrical energy. Vehicle life-km for fuel production energy use assumed as in Table 3.16.

    Source: Sypher (1995), based on DeLuchi (1991) and IBI (1978)

    Estimates of the quantity of upstream energy used for materials and fuel production as well as vehicle assembly, transport, retail and maintenance have been provided in Table 3.16. Table 3.17 compares the direct fuel used to operate motor vehicles with the upstream energy requirements.

    Energy is also required, both directly and indirectly, to build and operate roadway facilities, such as highway structures, road furniture and service buildings. Direct energy is the energy actually used in the construction. It represents the final transportation and installation of a component or assembly and is usually only a small percentage of the total energy used to build the structure. Indirect energy is the largest portion of embodied energy and represents the energy consumed in the production of building materials and their transportation during processing and distribution.

    Approximately 32 GJ or 826 L of crude-oil equivalent of energy is used to produce the asphalt for and lay 1 km of a four-lane highway. This value is exclusive of the energy required to prepare the ground for paving, the energy required to manufacture safety barriers and other road furniture (VHB Research & Consulting Inc. 1992), and the potential energy of carbon contained in asphalt.

    Table 3.17 Comparison of Upstream and Direct Energy Used by Vehicles
    Vehicle Lifetime


    Total Upstream Energy Used


    Fuel Consumption


    Upstream to Direct Energy Ratio
    Passenger car 160 000 1.70 3.85 44%
    Passenger van 200 000 1.97 4.75 42%
    Light 2-axle 240 000 2.86 7.58 38%
    Heavy 2-axle 960 000 2.78 8.66 32%
    5-axle 1 920 000 4.41 17.6 25%
    8-axle 1 920 000 5.65 22.8 25%
    Transit bus 1 260 000 4.30 19.3 22%
    Articulated bus 1 260 000 6.19 27.1 23%
    Note: MJ/km = megajoules per kilometre. Energy values given represent the equivalent electrical energy required, not the total energy required to produce that electrical energy.

    Source: Sypher (1995)

    Energy and the Urban Form

    By supporting sprawled development, transportation improvements can lead to a long-term reduction in energy efficiency. A study carried out by the United States Real Estate Research Corporation (1974) linked in-home energy consumption to land use density. The results were integrated into further work by Lang (1985).

    Table 3.18 shows the breakdown of energy used in-home and for transportation, by land use density. Between high-density, planned community and low-density sprawl, the energy used at home and for transportation almost doubles. Planned low-density development can save only about 10% of the total energy used by uncontrolled sprawl, whereas higher-density development significantly reduces energy consumption.

    3.4.2 Embodied Emissions and Other Impacts of Energy Use

    The environmental costs of fossil-fuelled, nuclear-powered and hydro-operated electrical generators, which may be used to generate energy for vehicle and road material construction, include a variety of environmental impacts (Cole and Rousseau 1992), such as:

    Table 3.18 Division of In-Home and Transportation Energy
    (trillion J/km2 per year)
    High-density, planned 61.5 37.6 99.1
    Planned mix 76.9 46.9 123.8
    Combination mix 76.9 56.4 133.3
    Sprawl mix 76.9 67.3 144.2
    Low-density, planned 103.5 60.9 164.4
    Low-density sprawl 103.5 74.9 178.4
    Source: Sypher (1995), based on Real Estate Research Corporation (1974). The difficulty of quantifying and monetizing the environmental impacts resulting from energy use varies. For example, the direct impacts of air emissions may be easier to measure than the long-term consequences of nuclear waste disposal. DeLuchi (1991) has provided a detailed accounting of greenhouse gases embedded in vehicles, fuels and other forms of automotive energy.

    About 35% of the crude oil that enters Canadian refineries is turned into gasoline (Environment Canada 1993). According to the International Energy Agency, environmental costs associated with petroleum production and distribution include (OECD 1989):

    • Oil well and processing site impacts,

    - loss of habitat and ecological damage,

    - air emissions during production, processing and transport,

    - aesthetic degradation, and

    - well brine and refinery wastes.

    • Oil releases and spills (major and minor), - tanker ship spills,

    - tanker truck spills,

    - pipeline spills, and

    - leaking underground storage tanks.

    • Catastrophic risk (accident, terrorism, war), - oil well and drilling platform blow-out, and

    - refinery, drilling or pumping facility explosion.

    Figure 3.3 Sources of Reported Freshwater Hazardous Material Spills in 
    British Columbia 1991-1992

    Source: MELP and Environment Canada (1993).Petroleum is released into water bodies from leaks and spills during extraction, processing and distribution, and by improper disposal of used crankcase oil. Leaking underground storage tanks, many used for motor vehicle fuel, cause groundwater contamination. Transportation is also responsible for a large portion of hazardous material spills. Oil and other hydrocarbon fuels represent the material most often spilled or released into both fresh and salt water bodies (Figures 3.3 and 3.4).
    Between April 1991 and March 1992, petrochemicals were reported as the source agent in 43% of a total of 506 hazardous material spills that occurred in British Columbia (MELP and Environment Canada 1993). Approximately 10 million litres of oil are spilled annually into the straits of Georgia and Juan de Fuca from recreational boats, commercial ships and land-based sources (RTEE 1993). Between 1972 and 1992, the federal government recorded 437 significant marine spills (Figure 3.5). A significant spill is defined as greater than 1 t or one that affects sensitive habitat.  
    Figure 3.4 Sources of Reported Marine Hazardous Material Spills in 
    British Columbia Waters 1991-1992

    Source: MELP and Environment Canada (1993).
    Figure 3.5 Significant Marine Spills Recorded by Environment Canada 1972-1992
    Source: MELP and Environment Canada (1993).
    3.4.3 Process Materials  
    In addition to the environmental impacts of energy used in manufacturing, all other industrial processes, such as smelting, kilning, distilling, drying, grinding and casting, result in solid waste, air emissions, habitat degradation and the depletion of nonrenewable resources. For example, the amount of greenhouse gases resulting from the manufacture and assembly of materials used in motor vehicles is quite large and is estimated at 10% to 15% of the emissions resulting from the whole gasoline production-and-use cycle. The cycle includes everything from the extraction and processing of fuels to construction of vehicles to the actual burning of the fuels in motor vehicles. The most significant materials by weight used in the construction of automobiles are listed in Table 3.19.
    Table 3.19 Estimated Material Consumption of an Average Motor Vehicle
    Weight (kg)
    % Total Vehicle Weight
    Steel 785.5 55.0%
    Iron 208.6 14.6%
    Aluminum 70.7 5.0%
    Plastics 102.0 7.1%
    Rubber  61.1 4.3%
    Fluids/lubricants 81.6 5.7%
    Copper 22.5 1.6%
    Glass 38.6 2.7%
    Zinc 9.1 0.6%
    Other Materials 47.5 3.3%
    Total Vehicle Weight 1 427.7 100.0%
    Source: Government of Canada (1991)

    One of the main sources of pollutants from the manufacture of automobiles is metal smelting. According to Statistics Canada (1989), the auto industry uses about 14% of all metal alloys produced in Canada and approximately 18% of all steel. Mineral production and metal smelting have many types of environmental and health effects. The use and processing of coal, iron ore and limestone for the iron and steel making process results in the creation of large amounts of sulphur dioxide emissions. In addition, iron and steel plants discharge toxic chemicals, such as ammonia, cyanide and phenolics, into adjacent areas (McRobert et al. 1991). The production of aluminum involves substantial land degradation in bauxite mining. Smelters are also a major source of sulphur dioxide and toxic substances such as gaseous hydrogen fluoride, particulate fluorides and alumina (EPA 1986). The negative environmental consequences of copper production include land degradation through open pit mines, water and soil contamination from mine tailings, and sulphur dioxide and heavy metal emissions from smelters.

    Construction Aggregates and Building Materials

    Large amounts of aggregate, including sand, gravel and rock, are required for road and parking construction and maintenance. In addition, smaller amounts are used in the production of concrete and other materials necessary for the construction of transportation-related infrastructure, such as parkades, gas stations, repair facilities, highway barriers and other road furniture. The removal of this material from quarries and gravel pits can have a variety of negative environmental impacts. Large open-pit quarries displace activities or land uses that existed before the pit was developed. Aggregate processing locations may also lower the aesthetic qualities and increase noise and dust levels for residents and visitors.

    Asphalt mix, a combination of aggregates and bitumen (heavy petroleum products), is the primary material used for the construction of road surfaces and bases in British Columbia. In addition to the costs associated with aggregate processing, asphalt mix production generates fugitive emissions, including SO2, NO2, volatile organic compounds, CO, CO2 and aldehydes (EPA 1986). These emissions are largely the result of the combustion process used to heat the asphalt mixture and vary depending on the production technique and control equipment used.

    Concrete is the main material used in the construction of bridges, some portions of roadways, and other transportation-related infrastructure such as buildings, curbs and highway barriers. Aside from the environmental impacts associated with the production of the necessary aggregate materials, concrete produces NOx, SO2, CO and CO2 (EPA 1991). These are emitted primarily from heating processes that occur during the manufacturing of the cement clinker. Cement manufacture is one of the main sources of human-produced CO2, which contributes to the enhanced greenhouse effect. Particulates and dust may also be a problem, usually originating from raw material storage, grinding and blending of materials, clinker production, finish grinding and packaging.

    3.5 Waste Disposal The average car in British Columbia lasts 8.6 years (Bein et al. 1996). During and after its operating life, each vehicle produces the following waste products: In addition, road construction and associated roadway facilities create large amounts of construction debris composed mainly of discarded asphalt and concrete structures.

    3.5.1 Used Lubricating Oil

    Used oil (if not properly disposed of) can degrade aquatic and terrestrial habitats. It contains toxic substances such as PCBs, benzene, lead, cadmium, toluene and chromium (Alford and Ouellette 1989). Oil bioaccumulates as it passes through the food chain, negatively affecting reproduction in many animals including bald eagles, seals and sea otters. Petrochemicals are also extremely toxic to certain species of fish such as salmon (MELP and Environment Canada 1993). Accordingly, waste oil and oil filters containing greater than 3% oil have been classified as special wastes under the provincial Special Waste Regulation.

    Historically, most waste oil filters have been sent to landfills, and large volumes of waste oil have been applied to the ground for dust control or poured into sewer systems. In recent years, this has been recognized as a significant environmental problem. Land disposal of used oil results in air emissions through evaporation of organic compounds from draining, dumping and landfilling, and contamination of surface and ground water by infiltration, migration and leaching of used oil contaminants. The proper disposal of used oil has been encouraged through the prohibition of the dumping of waste oil and oil filters in provincial landfills. Sellers of lubricating oil are required by law to accept waste lubricating oil at no cost. Currently, the preferred option for used oil and filters is recycling.

    Three different models were used to estimate the generation of used motor oil by passenger vehicles in British Columbia (Johnson 1995):

    The first model is based on total vehicle registrations and assumes that each vehicle type, either passenger or commercial, receives a specified number of oil changes of a particular volume in each year (R.W. Beck et al. 1993). Using this methodology, the estimated volume of used oil generated by passenger and commercial vehicles for 1992 in British Columbia is 17.5 million and 21.2 million litres, respectively. The second model is similar to the Washington model except that it uses ministry vehicle operating cost data (Bein et al. 1996) as inputs for the number of oil changes and the volume of oil used in each passenger-vehicle change. Estimated used oil production is 21.1 million litres. The third model is based on the number of predicted oil changes, both do-it yourself and mechanic-installed, for passenger vehicles in British Columbia (DesRosiers Automotive Consultants). Used oil generation is estimated to be approximately 17.4 million litres. These three estimates provide a mean value of 18.7 million litres of used oil for passenger vehicles (Table 3.20). Only the Washington model includes oil generated by commercial vehicles.  
    Table 3.20 Used Oil Generation Estimates
    Used Oil Generated For Passenger Vehicles 

    (million litres)

    Used Oil Generated For Commercial Vehicles 

    (million litres)

    Washington State 17.5 21.2
    Ministry VOC data 21.1 NA
    DesRosiers Automotive Consultants 17.4 NA
    Average 18.7 21.2
    According to the Ministry of Environment, Lands and Parks, Municipal Waste Reduction Branch, over 30 million litres of oil were collected in 1993. This indicates that exclusive of other sources of used oil producers, such as recreational vehicles and motorcycles, which are not accounted for in the table, approximately 10 million litres of used oil is being disposed of improperly.

    3.5.2 Waste Tires

    Improperly stored waste tires can have severe environmental consequences. Discarded tires are often stored in large piles that are not aesthetically pleasing and are a fire hazard. Tire-dump fires can produce vast quantities of oil and black smoke, degrading soil, air and water quality. These fires are also difficult and expensive to extinguish. When discarded at landfills, tires contribute to the consumption of valuable space.

    At major urban locations in British Columbia, the accumulation of huge amounts of tires in landfills and at tire dumps is no longer a problem. Under a program initiated in 1990, approximately 2.1 million passenger tires were collected for either energy recovery or recycling from April 1, 1992, to March 31, 1993. This is estimated by the Ministry of Environment, Lands and Parks to be nearly 100% of the new passenger and light truck tires used in the province during that time period (Grant 1994). In order to confirm this estimate, the total number of passenger and commercial vehicle tires generated in 1992 is calculated based on the methodology developed by R.W. Beck et al. (1993). It is assumed that each passenger vehicle generates one tire per year and 40% of heavy trucks generate one tire per year. The remaining trucks use recaps. Based on vehicle registration statistics, this produces a 1992 estimate of 1.5 million passenger vehicle tires and 200 000 commercial truck tires (Johnson 1995). While it appears that the annual number of generated tires is being recycled, the large number of tires generated over the past 40 years of road transportation remains unaccounted for in the current tire collection statistics.

    3.5.3 Lead Acid Batteries

    When improperly disposed of, automobile batteries can release sulphuric acid as well as heavy metals, such as cadmium, mercury and lead, into the environment (VHB Research & Consulting Inc. 1992). A battery return and recycling program has been in place in British Columbia since April 1, 1991. In 1993, 13 400 t of battery material or 352 632 batteries were recovered and recycled. This is 109% of the estimated 12 200 t of battery material, or 321 000 batteries, generated over the same period (Wallace 1994).

    As with tires, a large number of non-recycled batteries probably accumulated before the inception of the B. C. Battery Collection System’s transportation incentive subsidy. As the transportation incentive subsidy ensures that batteries can be profitably shipped to processors regardless of fluctuations in the price of lead, these pre-system batteries will likely be recycled over time. However, batteries that have been dumped in landfills or that remain stored in unsafe locations will continue to pollute the environment.

    3.5.4 Vehicle Bodies and Waste Dumping Sites

    After a vehicle is considered no longer useful, it must be stored and disposed of. Because of their value as scrap, most auto bodies are recovered through a network of salvage yards and scrap metal dealers. Eventually almost all auto bodies pass through this system, although the time between discard and recycling may vary.

    Most automobiles that are no longer roadworthy are delivered to a salvage yard where they are processed. This includes the removal of high-value parts, for example the engine and stereo, and, at some locations, the processing of fluids and used tires. What remains is the auto "hulk" which is sold to a scrap metal dealer following the salvage of all useful parts. If the hulk still contains fluids, such as transmission fluid, motor oil or gasoline, the fluids are removed and handled by a licensed disposal service. The typical hulk weighs 1134 kg, of which approximately 930 kg is recoverable (78% is steel recovery; 4% is nonferrous metals recovery), and the remainder is non-recyclable "fluff" or the residue of rubber, plastic and other non-metal materials.

    Automobile recycling contributes significantly to national production levels of some materials. The salvage of platinum from old catalytic converters, for instance, accounts for one-third of domestic platinum production. In addition to extending the life span of nonrenewable resources, metal recycling requires 50% to 74% less energy for production and releases 86% less air pollution, 76% less water contamination and 97% less solid waste than metal production from ores (Environment Canada 1993).

    The Insurance Corporation of British Columbia estimates that approximately

    25 000 cars and light trucks are damaged beyond repair each year. According to the Ministry of Environment, Lands and Parks, 16 836 t of metal hulk were recycled in 1992 (MELP 1993a). At 930 kg of recyclable material per vehicle, this represents approximately 18 000 vehicles, a recycling rate of 72%. This shortfall could represent actual conditions or under-reporting of the number of recycled hulks. However, as estimated by R.W. Beck et al. (1993), 99% of the auto bodies in Washington State are eventually recycled. It is reasonable to assume that a similar pattern occurs in British Columbia.

    The considerable amount of waste generated during the recycling process must also be noted. If 16 836 t of metal hulk were recycled in 1992 then 3000 t of fluff were removed from the vehicles and excluded from the recycling process. This can impose significant environmental costs through the corresponding transportation, storage and disposal of the waste.

    The disposal and storage of discarded cars and their component parts can have a negative impact on land use. When the appropriate recycling facilities and programs are not used, automobile disposal areas can be the source of large concentrations of harmful toxins and pollutants such as sulphuric acid and lead from batteries, ethylene glycol from antifreeze, hydrocarbons from transmission fluid, and used oils and heavy metals from brake fluid. Surveys have found that on average, each junked vehicle contains 6 L of lubricating oils, 5 L of cooling fluid and 3 L of sulphuric acid and fuel (Beard 1992).

    An informal survey was performed to provide an estimate of the land used by auto wrecking facilities in British Columbia. Twenty companies in the Lower Mainland and southern Vancouver Island were selected from the BC Tel yellow pages and questioned about lot size and the approximate number of vehicles situated in their yards. The average number of hectares per lot (1.28) was then extrapolated to the approximate number of wrecking companies in the province as listed in the yellow pages. The 258 registered wrecking companies were estimated to use a total of 331 ha of land throughout the province. At an average of 658 cars per hectare, the estimated number of scrapped vehicles in British Columbia at the time of the survey was 218 000 (Johnson 1995).

    3.5.5 Ozone-Depleting Substances

    Vehicle air conditioners produce one of the highest emission rates of all air conditioner and refrigeration systems.In British Columbia, the percentages are 37% and 21%, respectively (Table 3.21). Air conditioners are less prevalent in B.C., presumably due to climate milder than the Canadian average.

    Table 3.21 Vehicle Air Conditioners in British Columbia
    Number of Vehicles
    % with A/C
    Number of Vehicles with A/C
    CFC-12 per Vehicle (kg)
    Total CFC-12 (t)
    Emission Rate (%/year)
    Emission Total


    per year)

    Cars 1 330 014 37% 489 049 1.2 587 40 235
    Trucks 460 664 21% 97 876 1.5 147 40 59
    Total 1 790 678   586 925   734   293
    Notes: A/C = air conditioner. Source: MELP; total vehicles registered data provided by the Insurance Corporation of British Columbia.
    Most vehicles leak CFCs and must be recharged an average of three times during their lifetime. Vehicles are also involved in accidents or retired, at which time the release of CFCs is also possible. As a result, motor vehicle air conditioners are a significant source of CFC consumption and release. For example, in 1991, motor vehicles accounted for 23% of Canada’s CFC consumption. Approximately 13% of production in the United States is devoted to mobile air conditioners. CFC blown-foam products used in automobiles also contribute to ozone depletion. However, while the impact of foam products attributed to automobiles is significant, it is greatly overshadowed by emissions from mobile air conditioners.

    In the most current working values for ozone-depleting substances in British Columbia, the combined inventory of CFC-12 banked in cars and light trucks is estimated to be 734 t (Table 3.21).

    Recent provincial government legislation, being implemented between 1993 and 1997, reduces and will eventually eliminate CFCs originating from automobile air conditioners.

    • As of March 1, 1993, all sellers of CFCs are required to accept all returned chemicals and return them to the manufacturer for reclamation,

    • As of July 1, 1993, anyone who services air-conditioning equipment must use appropriate recovery/recycling equipment,

    • Beginning with the introduction of 1995 vehicle models, sales of new motor vehicles with CFC air conditioners are prohibited, and

    • Beginning January 1, 1997, existing vehicle air conditioners cannot be recharged with CFCs. If they must be recharged, they are required to be retrofitted to operate with a non-ozone depleting substance.

    While new contributions of CFCs are being reduced and will eventually be banned, current vehicle air conditioners continue to leak. In addition, wrecked vehicles that have not been properly disposed of may still contain ozone-depleting substances that will eventually be released some time in the future. Compounding the problem are previously released substances from vehicle air conditioners that have not yet reached the upper atmosphere and damaged the ozone layer. Because of the long survival rate of CFCs and halons, ozone destruction may persist through the 21st century.

    Based on the values provided in Table 3.21 and assuming that 25 000 vehicles are scrapped each year (Peat Marwick Stevenson and Kellogg 1992), almost 10 t of CFC-12 may be released to the atmosphere each year. This value is exclusive of recycling and other collection methods regulated and enforced by the recently adopted government legislation.

    3.5.6 Construction and Road Wastes

    Both asphalt-mix roadways and concrete structures are only useful for a finite period of time. Depending on the amount of use and environmental conditions, road surfaces and other structures need to be replaced periodically. Unless these materials are recycled, significant amounts of solid wastes must be disposed of at landfill sites or other dumping areas. These sites degrade the value of the immediate and surrounding area and consume space that could be used for alternative purposes such as agriculture, wildlife habitat, housing or recreation.

    While waste concrete is a significant component of the solid waste stream, the bulk of it comes from the demolition of buildings. The percentage of concrete from road-related wastes is relatively small. Sources in British Columbia include bridges and transportation-related infrastructure such as parkades, gas stations, highway barriers and other road furniture.

    In Europe, approximately 10% of construction demolition waste is recycled. In the United States, estimates place the amount of recycled concrete at less than 5% of annual disposal (Jakobsen 1991). More extensive reuse and recycling of concrete products are impeded by institutional and technological barriers. At present, the separation of concrete materials from other waste products is technologically difficult and not cost effective. Institutional difficulties include the lack of knowledge about availability, applications and cost for reused materials. In certain areas, there is also a reluctance by local authorities to change building codes to allow recycled materials wherever their suitability can be demonstrated. Experimental programs have, however, illustrated 100% recycling rates of concrete, at least over limited ranges of time (SCBC 1991). The most popular use for reprocessed concrete is for roadbed fill.

    Unlike concrete waste products, the recycling of asphalt and subgrade materials has proven technologically feasible. In-place recycling is a rapid construction method, and it provides 20% to 50% cost savings compared with removal and laying of new materials. Recycling of materials involves either "hot-in-place" recycling of pavement or the recovery of asphalt that is reprocessed off-site and reapplied as asphalt or sub-base mixes. The reuse of these materials offers the potential for significant savings in energy, bitumen and aggregates, while lessening demand upon bulk transportation and landfill operations (Olesen and Kennedy 1990).

    In British Columbia, hot-in-place recycling is used extensively. With this process, the road is heated and scarified to a pre-determined depth. The old material is rejuvenated chemically and is relaid in its original place.

    3.5.7 Non-Petroleum Liquid Wastes

    Aside from motor oil, the daily operation of automobiles is dependent on a variety of other fluids that can be environmentally harmful. They include engine coolant, sulphuric acid in batteries and transmission and brake fluid. These materials are toxic to both plant and animal life and can degrade local land and water supplies.

    Two fluids that must be changed and disposed of regularly for the proper maintenance of motor vehicles are engine coolant and transmission fluid. The amount of these two substances generated in British Columbia in 1992 was estimated with the use of published vehicle maintenance guides. Haynes Automotive Repair Manuals and Mitchell Domestic/Imported Cars and Light Trucks Service Manuals were used to calculate the average kilometres driven before a recommended change and the number of litres used at each change for selected models and years of cars and light trucks. Coolant is assumed to be a 50/50 mixture of tap water and antifreeze. Based on the Canadian annual average of 14 834 km driven for personal use (Long & Robinson 1993), approximately 4.0 million litres of waste coolant and 1.5 million litres of waste automatic transmission fluid were generated in 1992 (Johnson 1995). It must be noted that the suggested kilometre change indicators vary considerably depending on the type of vehicle use, location and personal vehicle maintenance habits.

    3.6 Water Pollution and Hydrologic Impacts Motor vehicles, roads and parking facilities are a major source of water pollution and hydrologic disruptions (Table 3.22). Water pollution and hydrologic impacts have been widely cited as a significant environmental costs (Works Consultancy 1993, OECD 1990, Miller and Moffet 1993, Dunne and Leopold 1978, Hanson 1992, ECOPLAN 1992, MELP 1993, US DOT 1993).Considerable research has been performed on various aspects of these impacts, but few studies have attempted to quantify and monetize their total effect. Although the loss of wetlands can be considered a hydrologic impact, it is included as a land use impact earlier in this chapter.  
    Table 3.22 Water Pollution and Hydrologic Impacts of Vehicles, Roads and Parking Facilities
    Water Pollution
    Hydrologic Impacts
    • Crankcase oil drips and disposal
    • Road de-icing (salt) damage
    • Roadside herbicides
    • Leaking underground storage tanks
    • Air pollution settlement
    • Increased area of impervious surfaces
    • Concentrated runoff, causing flooding
    • Loss of wetlands for water storage
    • Shoreline modifications
    • Increased water temperature
    Disruption from construction activities along shorelines and waterways, and through water courses and lakes
    3.6.1 Water Pollution Impacts

    Motor vehicles contribute to water pollution through air emissions and wastes that are washed into surface and ground water. Direct automobile water pollutants include petroleum products, tire and brake lining particles, rust and dust. One litre of oil can foul the taste of 4 million litres of drinking water, or make a 0.4-ha slick on surface water.

    During use, crankcase oil picks up toxic chemicals and heavy metals that harm the environment and human health unless disposed of properly. In the United States, an estimated 480 to 600 million of the 1.4 billion US gallons of lubricating oils used in cars are either burned by the engines or are lost in drips and leaks (Pressley 1991). Another estimated 180 million US gallons are disposed of improperly, typically poured onto the ground or into sewers. An estimated 46% of vehicles on the road leak hazardous fluids, including crankcase oil, transmission fluid, hydraulic fluid, brake fluid and antifreeze (Von Zwehl 1991). The oil spots and rainbow sheens of oil, common in puddles along roads and parking lots, are signs of this problem.

    Roads, parking lots and other impervious surfaces also impose hydrologic impacts that have costs separate from, and in addition to, water pollution. As stated by Dunne and Leopold (1978), "Modifications of the land surface during urbanization produce changes in the type or magnitude of runoff processes, and cause the planner many complex problems. The increased storm runoff leads to difficulties of storm drainage control, stream channel maintenance, groundwater recharge, and stream-water quality. Solutions to these problems are costly."

    Impervious surfaces reduce groundwater recharge, which results in reduced groundwater reserves, lower off-season stream flows and reduced wetland habitats. They also concentrate surface water flows, resulting in damage to riparian (streamside) corridors. Constriction of streams into culverts increases physical barriers to the movement of fish. These impacts impose costs in terms of environmental degradation, stormwater management, flood prevention, public water supplies, fisheries, agriculture, recreation, aesthetics and cleanup requirements.

    Solar heating of paved surfaces and reduced shade-giving vegetation along roadways tends to increase the temperature of stormwater runoff (Waste Management Group 1992). Even a small increase in water temperature can reduce or eliminate sensitive insect and fish species, and tends to increase organisms’ sensitivity to toxic metals.

    3.6.2 Road and Urban Runoff Pollutants

    Due to automobile fluid drips and particulate deposition, stormwater runoff from roads and parking lots is a major source of water pollution and hydrologic impacts. While roadways occupy only 5% to 8% of urban watershed catchment area, roadway drainage contributes as much as 50% of total suspended solids, 16% of hydrocarbons and 75% of metals discharged into streams (Works Consultancy 1993). These are considered "non-point" water pollution sources, which means that they originate from numerous dispersed sources and are therefore difficult to control. According to the Urban Runoff Control Guidelines published by the British Columbia Ministry of Environment, Lands and Parks, "non-point sources (NPS), such as stormwater runoff from urban and agricultural areas, are the major continuing source of pollution to receiving waters. Non-point source pollution is often the limiting factor in improving or maintaining surface water quality, and urban surface runoff is second only to agriculture runoff as a source of NPS pollution." (Waste Management Group 1992).

    Table 3.23 Percent of Urban Runoff and Combined Stormwater Overflow as a 
    Contribution to Impaired Water Bodies in the United States
    Water Body
    Urban Runoff
    Combined Stormwater Overflow
    Estuaries Area 53% 4%
    Ocean Coasts Length 36% 3.6%
    Lakes  Area 29%
    Great Lake Shoreline  Length 6% 7.5%
    River Length 9.6% 2.8%
    Source: Weiss (1993)
    According to the National Water Quality Inventory 1990 Report to Congress, urban runoff and combined sewer overflows (when sewage system capacity is exceeded during heavy storms so urban runoff is released with little or no treatment) are major sources of impairment for water bodies, as shown in Table 3.23. The table indicates that urban runoff is a major contributor toward water pollution problems in the United States. As described in this section, roads and motor vehicle use are major contributors toward pollution loading of urban runoff.

    Several studies have measured pollution concentrations and quantities in road and urban runoff. Published stormwater pollutant concentrations and standards are summarized in Table 3.24 (Waste Management Group 1992, Lorant 1992). The table illustrates that storm water pollution concentrations often exceed limits for the protection of aquatic life. As described in Table 3.25, many of these pollutants originate from motor vehicle use.

    Studies indicate that automobiles are the primary source of most metals and organics found in stormwater runoff (Weiss 1993). A mass-balance study of urban runoff in California’s Santa Clara Valley shows that 67% of zinc, 50% of copper and 50% of cadmium originates from motor vehicles (Weiss 1993). A study based in Madison, Wisconsin, of heavy metals, polycyclic aromatic hydrocarbons, bacteria, pesticides and suspended solids in urban runoff concluded that runoff from streets and parking lots had the highest mean concentration of all contaminants except zinc from industrial roofs and phosphorus from residential lawns (Bannerman et al. 1993). Table 3.25 describes the specific origin of roadway runoff pollutants, indicating that most result from automobile use, the roadway itself and highway maintenance.

    Table 3.24 Summary of Typical Stormwater Pollutant Concentrations
    Urban Runoff
    Highway Runoff
    Limits for Protection of Aquatic Life
    Suspended Solids (mg/L)
    2-2 890
    10 if background < 100 mg/L: otherwise 10% of background
    Biological Oxygen Demand (BOD) (mg/L)
    Chemical Oxygen Demand (COD) (mg/L)

    1 031

    34-1 291
    Lead (g/L) 
    3-28 000
    10-3 775
    Copper (g/L)
    Zinc (g/L)
    10-5 750

    25 500

    Cadmium (g/L)
    Chromium (g/L)
    < 10-110
    Nickel (g/L)
    < 2-126
    Arsenic (g/L)
    Phthalate Esters (g/L)
    Varies, 0.2 - 4
    PAHs (g/L)
    < 0.01-12
    0.1 BaP
    Total Phosphorus (mg/L)
    Up to 0.7
    Alkalinity (mg/L)
    Recommended > 20
    Notes: NA = not available. PAHs = polycyclic aromatic hydrocarbons. BaP = benzo(a)pyrene.

    Source: Waste Management Group (1992)

    State highway stormwater contribution to selected water quality concerns in Washington State were studied. The results, summarized in Table 3.26, indicate that highway runoff is a moderate contributor to these problems. This does not include runoff from local roads and streets.

    Although Table 3.24 shows that total metal concentrations in undiluted urban runoff routinely exceed water quality standards for the protection of habitat, they are mostly in a solid phase and not immediately harmful to plants and animals. Changing conditions can re-solubilize metals. For example, lead can be released from particles if the receiving waters are more acidic or have a higher chloride concentration than the runoff. Iron, zinc and manganese can also precipitate as hydroxides under oxidizing conditions. While concentrations of some pollutants, such as lead and PCBs, may decrease due to recent pollution reduction efforts, others are likely to increase from growing automobile use and urban sprawl.

    Most analyses of roadway stormwater impacts assume a threshold below which pollution is not a problem. For example, this allowed the 1985 United States FHWA study to conclude that highway runoff is unlikely to be a problem if the highway carries less than 30 000 average daily traffic and runoff is diluted at least 100 to 1 in receiving stream flows. However, such assumptions are controversial, especially for carcinogens and toxins such as heavy metals, which can be harmful in small concentrations and which may become concentrated by chemical or biological processes. Thus, even where stormwater pollution is not considered a problem by conventional standards, vehicle use may produce significant water pollution costs.

    Table 3.25 Road Runoff Constituents and Their Primary Sources
    Primary Source
    Particles Pavement wear, vehicles, atmosphere deposition, highway maintenance
    Nitrogen, phosphorous Atmosphere, road fertilizer
    Lead Leaded gasoline (vehicle exhaust), tire wear, lubricating oil, grease, bearing wear
    Zinc Tire wear, motor oil, grease
    Iron Autobody rust, steel highway structures, automobile parts
    Copper Metal plating, bearing wear, engine wear, brake lining, fungicides and insecticides
    Cadmium Tire wear, insecticides
    Chromium Metal plating, moving engine parts, brake lining wear
    Nickel Gasoline, diesel, lubricating oil, metal plating, bushing wear, brake linings, asphalt
    Manganese Moving engine parts
    Bromide Auto exhaust
    Cyanide Anticake compound for de-icing salts
    Sodium, Calcium De-icing salts, grease
    Chloride De-icing salts
    Sulphate Roadway beds, fuel, de-icing salts
    Petroleum Spills, leaks, engine blow-by, antifreeze and hydraulic fluids, asphalt leachate
    PCBs PCB catalyst in synthetic tires, atmospheric deposition
    Pesticides Sprayed on highway rights-of-way, atmospheric deposition a
    Rubber Tire wear
    Asbestos Clutch and brake lining wear
    a. Pesticides are not used on British Columbia highway rights-of-way. Source: Lorant (1992).
    Total automobile water pollution may be significantly greater than indicated by roadway stormwater measurements. According to German experiments cited in Lorant (1992), only 5% to 20% of the pollution produced by motor vehicles that eventually settles onto land is discharged in highway runoff. Wind and vehicular turbulence distribute 80% to 95% of the pollution to other areas. At least some of these pollutants eventually find their way to water bodies. How much is unknown, and their environmental impact at such low concentrations is uncertain (Lorant 1992). The influence of motorway-related pollutants may extend 70 m from the pavement edge, depending on traffic density (Waste Management Group 1992).  
    Table 3.26 Washington State Highway Contribution to Water Quality Concerns
    Water Source
    Water Quality Concerns
    Highways Contribution


    Lake Martha Residential lake Algae, nutrients, sediment, bacteria
    Lake Union Urban lake Bacteria, heavy metals, toxic organics
    Spokane Aquifer Groundwater Bacteria, heavy metals, toxic organics
    Garrison Creek Small salmon creek Erosion, sedimentation, heavy metals, oil, grease
    Yakima River Large river Sediment
    Source: ENTRANCO (1992)
    3.6.3 Environmental Damages

    The pollutants from road and urban runoff can harm plants and animals when initially released. They often concentrate in sediments, causing future damage. The following water pollution impacts are generally associated with highway runoff (Lorant 1992):

    • Dissolved oxygen depletion: Generally the biological oxygen demand (BOD) is less than 30 mg/L, based on urban stormwater data. High BOD is the consequence of abnormal concentrations of pollutants stimulating algae growth. Excessive algae populations deplete the oxygen available in a body of water for other organisms, harming or killing wildlife. There is no data on BOD specific to highway runoff,

    • Nutrients: Urban stormwater runoff can contain ammonia and nitrate levels in excess of those recommended by regulatory agencies. Excessive nutrients can create accelerated growth of nuisance aquatic plants in water bodies and lead to oxygen-depleted conditions,

    • De-icing agents: The effect of de-icing agents (salts) on receiving waters and nearby soils is well documented in the literature. Road salts can show high accumulations in lakes and wetlands above the Canadian and United States criteria of 250 mg/L,

    • Metals: Metals tend to settle in runoff sediments, where their concentration can be an order of magnitude higher than background sediment levels. Metal concentrations in sediments show a close correlation with traffic volumes. High metal concentrations are toxic. Even relatively low concentrations can harm some predator species, since these substances bioconcentrate in the food chain, and

    • Biological impacts: Experiments show severe algae inhibition when exposed to 1%, 5% and 10% runoff concentrations with very high average daily traffic (ADT) of 185 thousand after two weeks of dry weather. Runoff from 23 000 and 16 000 ADT on rural and suburban highways, preceded by a brief dry period, generally stimulated algal growth. Rainbow trout showed no toxic effects with filtered runoff from highways of 50 000 ADT, but unfiltered runoff was toxic in both undiluted and 50% diluted samples. Runoff filtered through a 60 m grassy ditch was not toxic to trout.

    Tests showed minimal acute toxicity of undiluted highway runoff for amphipod, isopod, water flea, mayfly and fathead minnows. Decreases in abundance and diversity of bottom-dwelling organisms, and accelerated eutrophication of lakes have been attributed to urban runoff. However, these effects have not been demonstrated for highway runoff. Chloride salt concentrations exceeding 1000 mg/L increase the drift of bottom-dwelling micro-invertebrates, decrease biomass and diversity of algae species, and decrease the density of bacteria in streams.

    A Washington State Department of Transportation study of state highway stormwater water quality and hydrologic impacts found that untreated stormwater runoff is unsafe for people to drink and unhealthy for fish (ENTRANCO 1992). It contains toxic metals, organics and other compounds that can be harmful. Even swimming in stormwater runoff is unpleasant and not recommended. Stormwater’s chemical make-up and the problems it may cause vary greatly from one area to another depending on land uses, local human activities, the sensitivity of receiving water bodies and how the water is used. Different standards exist for drinking water, swimming water and water for wetland habitat.

    Hydrologic impacts of stormwater also depend on the amount of paved surface, so impacts are generally proportional to lane kilometres. The design of highway structures can also affect aquatic wildlife habitats. A 1992 survey of 726 culverts in Washington State found that 36.4% interfered with fish passage some percentage of the time, of which 17.4% were total blockages (Burns et al. 1992).

    Water quality impacts are more closely related to traffic volumes and to drainage management. A United States FHWA report (Lorant 1992) states that highway runoff is unlikely to have adverse effects on receiving waters if:

    • no public water supply uses the receiving water,

    • the highway has less than 30 000 vehicle average daily traffic, or,

    • highway runoff is conveyed by overland flow in an unlined or grassed channel, at least over a distance of 60 m prior to discharge into the receiving stream, or,

    • highway runoff is diluted at least 100 to 1 in receiving stream flow.

    According to an urban runoff study for British Columbia agencies, the pollutants in stormwater runoff that should receive the highest priority for removal are primarily those that are associated with automobile use (BCRC 1991). These include suspended solids, toxic metals, oils and grease, and hydrocarbons (particularly polycyclic aromatic hydrocarbons).

    3.6.4 Hydrologic Impacts

    Roads and parking lots also alter the normal hydrologic process (Dunne and Leopold 1978). Rather than percolating into the ground, precipitation washes over the surface into natural or artificial watercourses. The consequences are many, including reduced groundwater recharge, increased surface water runoff volumes and peak flow rates, flooding and erosion, habitat damage, lower dry season flows, increased water management costs and wetland loss. Reduced plant canopy along roads often increases water temperatures, which can harm aquatic wildlife. In many cases, the hydrologic impacts of road and urban runoff are more harmful to receiving waters than the effects of toxic pollutants (Waste Management Group 1992). These hydrologic impacts are often dispersed and cumulative, with roads and parking lots bearing a portion of the responsibility for the total costs of flooding, flood control and environmental damage.

    3.7 Barrier Effects Barrier effect, a consequence of the existence of a road facility on the human community and on the ecosystems traversed by it, is also called severance. Severance becomes obvious when a new road (rural or urban) or a large parking lot is constructed in the midst of an existing community or habitat. The impacts are most prevalent with roads with high traffic volumes. Traffic accidents involving pedestrians and bicyclists in urban areas, and wildlife kills on rural roads, are the most graphic indications of the severance problems.

    3.7.1 Roads as an Obstacle to Human Activities

    Although roads and other transportation facilities are usually thought of as facilitating mobility, they also create barriers to movement, especially to non-motorized traffic. Crossing roads with vehicle traffic on them and moving along with traffic as part of a detour necessary to cross a facility cause delays, discomfort and danger to pedestrians and bicyclists. The consequences are felt in additional movement required and in changes to previously established meeting patterns, often leading to reduced access to desirable destinations, longer trip times and distances, and increased reliance on motorized travel. Barriers mostly affect children, the elderly and people who are physically disabled and financially disadvantaged, because they frequently must rely on non-motorized modes of transportation.

    The Scandinavian countries have been leading in operationalizing models that consider the severance and hazard aspects in road planning. Swedish National Road Administration’s Calculation Guide for Investments in Roads and Streets (SNRA 1986), for example, outlines detailed procedures for assessing the travel time and accident hazard aspects of the barrier impact at the project level. Currently, the Ministry is adapting the Swedish model to British Columbia needs (Rintoul 1995). There are two principal groups of variables in the model: (1) traffic and road facility characteristics, and (2) descriptors of the community with variables such as age and income distribution, and the need to cross the road facility. The same model, but with different descriptors of the community, can also be used to quantify the barrier effect of roads on agricultural activities.

    Although the impacts are strongest when traffic is present on the road, the consequences of the barrier are also felt when little or no traffic is present on it. For humans, this occurs where road facilities are relatively wide, elevated or depressed with steeply sloped embankments, or flanked by drainage ditches, security fences or noise-attenuating furniture. For animals, vertical structures such as retaining walls, sound walls and concrete safety barriers are particularly disturbing.

    The impact that motor vehicle traffic can have on local movement, and thus on neighbourhood behaviour has been studied by urban planners. Appleyard (1981) reported a negative correlation between traffic volumes and various measures of neighbourly interactions and activities, including number of friends and acquaintances residents had on their street, and the area that they consider "home territory." Hillman (1988) emphasizes the lack of consideration of this cost in transportation planning: "Preferred patterns of behaviour are altered and an increasing burden of responsibility is imposed on all road users, especially pedestrians, to reduce their exposure to risk. This is a social cost which has hardly been acknowledged and which certainly is not reflected in government transport or road safety policies."

    Freund and Martin (1993) stress the inequity aspect of traffic barriers to children and the elderly: "Perhaps since the dependence and relative powerlessness of children is taken for granted in all areas of life, their special problems with regard to automobility go unnoticed. Since they cannot yet participate in a system of automobility, children are dependent on being chauffeured by their elders, or must make do with often inadequate mass transit, or with walking and biking–both of which are most difficult and somewhat dangerous in auto space." Concerning the elderly, "...public transit is often inaccessible and walking is made more dangerous by traffic conditions that favour the auto, including wide roads that have brief green lights for cross streets. Also, while walking is a viable form of transport and exercise for the elderly, pedestrian facilities are inadequate or non-existent..."

    Those affected by the barrier aspect of transportation also include people who choose to forgo their automobile use. As pedestrians and cyclists, their positive travel behaviour is not reinforced when they encounter traffic barriers, noise and fumes.

    3.7.2 Highways as Barriers to Wildlife

    Many large species of wildlife use the most easily accessible and productive areas of the landscape as movement corridors and as prime habitat. Often these areas are located in valley bottoms or along streams or rivers. Unfortunately, these prime habitat areas are also the easiest and cheapest locations to place highways. Transportation corridors frequently bisect prime habitat areas and major migration routes that wildlife use to search for food, shelter and mating partners, resulting in significant wildlife impacts.

    The barrier effect of roadways to wildlife migration depends on traffic speed, highway use, crossing distance, characteristics of the terrain or vegetation paralleling the road and abundance and migration patterns of local wildlife populations (Bellis and Graves 1971, Bashore et al. 1985). The use of the highway as a corridor for undesirable and introduced species is also a function of the local or regional wildlife populations.

    One of the direct consequences of the barrier effect of highways on wildlife movement are vehicle-wildlife collisions. A cautious estimate places the number of birds and mammals killed on Canadian roads at more than two million annually (Oxley et al. 1976). In British Columbia, the Wildlife Accident Reporting System operated by the Ministry of Transportation and Highways reported 3780 wildlife accidents in 1983 (MoTH 1995). As animal kills are only reported when a carcass is located on or near the roadway, the assumption is made that for every wildlife accident up to five accidents may go unreported.

    Wildlife-traffic collisions are a function of traffic speed, highway use, crossing distance and abundance and migration patterns of local wildlife populations. The populations that would be the most severely affected are those that are forced to cross major routes, those with low reproductive success or those stressed by some other external source of mortality such as hunting.

    Certain species may be able to absorb losses resulting from traffic-related deaths to an extent that the existence of the population is not threatened. However, research has shown that vehicle accidents can be a significant source of mortality (Fuller 1989). For example, from 1964 to 1978, Flygare (1980) reported that the Trans Canada Highway accounted for 60% of the elk killed in the Bow River Valley corridor. While no exact aggregate value estimating the threat to biodiversity has been calculated, road mortality in conjunction with habitat loss and the disturbance of migration and general movement can potentially extirpate species from certain areas or in a worst case scenario, drive them to extinction.

    Aside from the direct mortality associated with roadway crossings, roads are a barrier to the movement of land mammals (except bats), reptiles, amphibians and non-flying invertebrates. This barrier effect can be exacerbated by concrete dividers. In the vicinity of wetlands, migrating amphibians often suffer enormous losses as a consequence of these barriers. Aquatic species that inhabit streams or rivers may also be affected by road placement. One misplaced culvert has the potential to block the return of an entire run of spawning fish.

    Roads may also serve as psychological barriers to animal movement and nearby habitation. Diamond (1972) found that some birds resisted crossing a road only a few yards wide. Oxley et al. (1974) regarded divided highways with clearances of 90 m or more as possibly the equal of freshwater bodies twice as wide in barring the passage of small forest mammals. Certain large mammals avoid highways even though they cross them if necessary. Grover and Thompson (1986), Irwin and Peek (1983) and Lyon and Jensen (1980) found that elk avoided areas close to roads. Bald eagle nesting sites were negatively correlated with roads (Anthony and Isaacs 1989, Livingston et al. 1990), as were sandhill-crane roosting areas (Krapu et al. 1984). Van Dyke et al. (1986) reported that cougars in Arizona and Utah likely avoided roads and that dirt roads were crossed more frequently than hard-surfaced roads.

    On the other hand, the forage and the remains of dead animals associated with highway rights-of-way may attract certain species (Case 1978). In New Zealand, possum kills by traffic at night is currently a major controlling factor for this introduced species. However, predatory birds introduced to control the possum population feed on the possum remains on the roads and are also killed or injured by traffic (Bein 1995a).

    The disruption of continuous habitat by roads may impede migratory patterns or normal behaviour necessary for species propagation and access to food and water or denning areas. Depending on the sensitivity and adaptability of the species, this disruption could curtail species success. Alternatively, road corridors can allow certain competitive species access to previously inaccessible areas (Box and Forbes 1992). This introduction can disrupt the balance of the pre-roadway ecosystem and lead to the elimination of some species.

    3.7.3 Roads as Barriers to Farm Operations

    Roads are usually thought of as an infrastructure needed to support agriculture. Access to farms to bring supplies and labour, and to haul away crops are necessary for an efficient functioning of commercial agriculture. In developed areas that are already served by a system of farm roads, however, additional road developments for general transportation needs are often in conflict with agricultural activities in the area. The conflicts take place during construction and, more importantly, during the lifetime of the new facility. In planning roads that will bisect existing agricultural areas, the severance effects must be taken into account, in addition to the direct impacts of land take, propagation of the urban shadow, air pollution damage to crops and contamination of arable soils and irrigation water.

    The British Columbia Agricultural Land Commission (ALC) has worked out the most important severance effects of roads on agriculture (Plotnikoff 1995, Hornell 1995). These can be described as direct operational severance and indirect degradation of the farming community through mechanisms such as farm disinvestment, increased non-farm ownership and collapse of farm-support infrastructure. Locating a transportation corridor along the non-farm edge of a large agricultural area can act as an effective buffer to permanently define urban and non-farm areas and to unify larger agricultural units.

    Farm operations severance takes place because a farm is viable for a particular range of cropping options at one size. The optimal size could be severely compromised if it were cut into two or more parcels by roads. Each parcel could then be too small to be economically managed as a farm unit. A transportation corridor through farmland can also limit the farmer’s ability to efficiently and effectively manage the farm as a whole. For example, severance of a farm may require an operator to travel long distances to reach that part of his unit severed by a corridor. Road development projects may also sever farm roads, irrigation systems and drainage systems on which farming depends.

    Major road developments in farming areas can create the impression of eventual urbanization which causes farmers to lose hope in the future of local agriculture. The early symptoms of degradation may include increasing non-farm ownership and disinvestment on the remaining farms, when farmers begin to "mine" the soil and leave lands idle. Farm support institutions may start to disappear at the same time.

    3.8 Transportation and Biodiversity The negative impacts of road transportation are incurred by the environment as a whole, but the majority of the impacts affect the most sensitive component of the globe: living organisms. Air pollution, inefficient land use, waste disposal, water pollution, hydrological impacts and resource consumption all contribute to the discomfort, loss of productivity, illness and even death of humans and thousands of other species. The aggregate effect of these impacts can modify the biosphere through a reduction in the number of living organisms and a loss of species.

    Species loss is the result of a variety of intertwined components of which transportation is only one. As with most environmental problems, poorly planned, unrestrained industrialization, population growth and the overuse of finite resources are the determinants in the current global crisis of species extinction.

    While the "road kill" may be the most dramatic aspect of highway-wildlife interactions, it represents only one small component of the damages that both flora and fauna are subjected to as a result of road construction and use. Roads may also contribute to less visible, but more harmful habitat loss, fragmentation and insularization, as well as general disruption of the normal behaviour and movement patterns of affected species. Roads not only affect large mammals such as deer and moose, but also plant life, small mammals, amphibians, reptiles, birds, fish and microorganisms. Thus, roads can decrease biodiversity as a whole.

    3.8.1 What Is Biodiversity?

    Biological diversity, called biodiversity, is widely recognized at three different levels (Noss 1990):

    Probably the most important component of biodiversity from an ecological perspective is that found at the ecosystem level. Depending on their character, healthy ecosystems cycle the basic elements of all life: water, gases and nutrients, and provide ecosystem services that regulate the planet. Wetlands, for example, filter and clean water as well as ameliorate water flow, reducing flooding. Healthy forests act as a carbon sink helping to regulate the carbon content of the atmosphere.

    Maintaining diverse and viable populations of wild plants and animals is of critical importance to human society and to the health of the global environment. The diversity of species is necessary for the normal functioning of ecosystems and the biosphere as a whole. From a purely utilitarian perspective, biodiversity is vital to our economic prosperity.

    Species diversity provides people with a host of wild and domestic plant, fish and animal products. These products are used to produce a variety of goods including: food, fibre, medicines, cosmetics, industrial products, fuel and building materials. Currently, one quarter of pharmaceuticals dispensed in the United States contain active ingredients derived from plant products (WRI 1994) and humans rely on about 20 plants for their diet, yet more than 75 000 plant species are known to have edible parts. It is impossible to predict what benefits could be derived from species that have not yet been investigated, or how many benefits we will forego by allowing undiscovered species to fade into extinction.

    Genetic diversity is important for maintaining and establishing healthy productive crops. Unique genetic characteristics of some crop species leave them resistant to certain pests and diseases. These traits allow farmers and foresters to select resistant crops when faced with infestations, rather than resigning themselves to heavy pesticide use or high crop loss. This variety of crop species results in greater productivity and increased market sales.

    The loss of genetically distinct populations within a species is, at the moment, at least as important a problem as the loss of entire species. Once a species is reduced to a remnant, its ability to benefit humanity ordinarily declines greatly, and its total extinction in the relatively near future becomes much more likely. By the time an organism is recognized as endangered, it is often too late to save it (Ehrlich 1988).

    If healthy, biologically diverse ecosystems are to be maintained, the smaller genetic and species elements must be accounted for first. If biodiversity is lost at the genetic level not only will the geneplasm necessary for crop production be lost, but the life-giving services of the ecosystem could also be threatened. Biodiversity at the genetic, species and ecosystem levels is linked and should be protected as a complete system. For example, the destruction of insects can lead to the failure of crops that depend upon insect pollination. Furthermore, pesticides can result in the extermination of insect pests, thus terminating the natural pest control abilities of an ecosystem, leading to severe pest outbreaks that require further chemical treatment.

    3.8.2 Biodiversity in British Columbia

    British Columbia is Canada’s most biologically diverse region, comprising approximately 10% of Canada’s land area but accounting for over half of its vascular plant and vertebrate animal species. A rich variety of habitats, including forests, grasslands, meadows, wetlands, rivers and intertidal and subtidal zones support 143 mammal species, 454 birds, 20 amphibians, 19 reptiles and 450 fish species. An estimated 2850 vascular plants, 1000 mosses and liverworts, 1600 lichens, 522 species of attached algae and well over 10 000 fungi species are also thought to exist (MELP undated). The number of invertebrate species, including insects, is unknown. More than a miilion species of invertebrates, most of them insects, were collected from the upper Carmanah Valley. 150 thousand have been sent around the world to taxonomists for identification; of this number 67 confirmed new species have been identified. Researchers estimated that at least 600 new species will eventually be discovered (WCWC 1995).

    Of species native to Canada, 9% of the breeding birds, 12% of the reptiles, 17% of the mammals, excluding marine mammals, and 27% of the amphibians are exclusive to British Columbia. Population sizes of a number of species in the province also have global significance. The province has 75% of the world’s stone sheep, 60% of the world’s mountain goats, 50% of the world’s blue grouse, at least 50% of the world’s wintering trumpeter swans and 25% of the world’s grizzly bears and bald eagles (MELP and Environment Canada 1993).

    In British Columbia (MELP undated), 103 wildlife and freshwater fish species are on the Red List (designated, or are being considered for designation, as endangered or threatened) and another 97 are on the Blue List (considered vulnerable). Some 634 vascular plant species in British Columbia are rare, and of these, about 170 are considered threatened or endangered. From a national perspective, 236 species, subspecies or populations of native wild plants and animals were listed as "at risk" by the Committee on the Status of Endangered Wildlife in Canada (Environment Canada 1993). This includes 52 endangered, 53 threatened and 111 vulnerable plant and animal species. In total, 9 species are known to have become extinct, and an additional 11 have been extirpated since Europeans arrived in Canada.

    3.8.3 Preserving Biodiversity in British Columbia and Canada

    It is widely accepted that the greatest threat to biodiversity is habitat loss. While direct human exploitation such as hunting or poaching may receive attention, the habitat destruction that inevitably results from the expansion of human populations and human activities should be the primary concern.

    Habitat loss takes many forms. The most obvious is the outright loss of areas used by species. This can be through the direct conversion of use such as forested land to urban development that has almost no habitat value. The degradation of habitat, while not completely altering the habitat qualities of an area, can lower the value of the habitat or exclude certain species. For example, the conversion of a wetland to a road right-of-way will deprive many native species of food, shelter and breeding areas, and greatly reduce the biodiversity of that land. Habitat fragmentation is the third form of habitat loss or reduction. This is a consequence of human-induced landscape modification forcing native species onto small patches of undisturbed land surrounded by areas cleared or modified for other purposes, such as highways.

    Historically, it was thought that the conservation of biodiversity could be facilitated with parks and other protected areas. About 70 million ha has been protected in Canada (Table 3.27). However, managed as separate self-contained entities, without consideration for the surrounding area, they risk becoming isolated habitat fragments surrounded by human-dominated areas. The result would be parks and reserves too small to support viable populations of some of their larger carnivores and herbivores. For example, eight grizzly bears require 600 km2, eight cougars require 760 km2 and eight wolves require 600 km2 (Sullivan and Shaffer 1975). Eight individuals is modest compared to the suggested 500 necessary for long-term population viability (Franklin 1980, Seal 1985). Very few parks are large enough to provide the extensive tracts of habitat necessary for large mammals such as grizzly bears and cougars.

    In addition to simply setting aside areas as isolated protected habitat patches, policy makers and planners are attempting to apply integrated resource management principles outside the protected areas. The approach entails co-ordinating government agencies, community leaders, businesses and private groups within a region so that biodiversity concerns are included in the planning process. Only by integrating the management of landscapes with protected areas can the habitat needs of broad-ranging species be accommodated.

    The federal Green Plan, the British Columbia Ministry of Environment, Lands and Parks, the British Columbia Round Table on the Environment and the Economy, the multi-stakeholder Dunsmuir II group and many others have recognized the need for the preservation of biodiversity. CORE (1994) stated that proper land use planning and management is an important element of a strategy to conserve biodiversity. British Columbia is one of the few areas in the world to attempt to comply with the United Nations recommendation to preserve 12% of representative ecosystems. Between May 1992, when the provincial government announced its Protected Areas Strategy, and August 1994, 64 new parks were created. This amounted to an increase in protected area from 6% to 8.1%, or 77 300 km2, approximately the size of Scotland or New Brunswick (Government of British Columbia 1994).

    Table 3.27 Major Groups of Protected Areas Owned or Managed by Governments in Canada
    Types of Protected Areas
    Area (ha)
    National Parks or Park Reserves
    Provincial or Territorial Parks
    Ecological Reserves
    Wilderness Areas
    Nature Trust Areas
    Migratory Bird Sanctuaries
    National Wildlife Areas
    Wildlife Management Areas
    Wildlife Protection Areas
    Heritage Areas or Parks
    Historic Areas or Parks
    National Capital Commission Areas
    Provincial Conservation Authority Areas
    Source: Turner et al. (1991)
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