Zagreb is quite a compact city and it is possible to walk between most of the major tourist attractions. The strict city centre is pedestrianised, while traffic in the Upper Town is heavily restricted.
If you get tired of walking, or want to go a little further out, you can use public transport provided by trams and buses. The trams serve the city proper, while the buses go to the suburbs and the hilly northern parts of the city. The service is generally good, but gets very busy in the rush hours. Trams run in 5 to 15 minute intervals (depending on the line and time of day) from 5 am until midnight, while outside these times night trams take over (these go every 45 mins or so). Bus timetables vary greatly from line to line, and night buses exist on the most popular routes. Map and schedules are available from ZET (although the amount of information in English is rather limited at the moment).
A tram or bus ticket for zone 1 (covering most of the city) will cost about �0.65/�1 if bought outside the vehicle (any newsagent will sell them), or a little more if bought from the driver. Ticket prices then increase with the number of zones if you go into the suburbs. When entering the vehicle, you must invalidate (stamp) the ticket in one of the orange machines. It is then valid for a single journey with unlimited changes for 90 mins. You need a second ticket to return. Day tickets at �1.60/�2.20 are very good value if you plan multiple journeys. Tram tickets are also valid on the Upper Town funicular.
There is a large number of taxis and taxi ranks throughout the city, plus they can be booked over the phone. The taxi service is generally very good, but is expensive for most Croats, so it�s usually very easy to get one.
If you intend to drive around Zagreb, please be aware that it�s obligatory to have dipped headlights on at all times, even during the day, and that the allowed level of alcohol in the blood is zero (0.0%). It is best to avoid the rush hour like in all big cities. Outside the rush hour, the roads are busy, but manageable. Croats are not very considerate when driving, so do take care � for instance, nobody will let you in if you�re waiting to enter a major road, and people will often cut across your path with little or no warning. Please note that the older part of town is a network of one-way streets that can be confusing at times, while the strict city centre is pedestrianised and the Upper Town restricted to residents and government vehicles. Having said all this, people used to Mexico City won�t have any problems, and may well find that the traffic in Zagreb positively flows, and the Croats to be courteous and disciplined drivers!