Red - Current maintenance tunnels (already created)
Blue - Future maintenance tunnels (not made yet)
Green - hallways (same floor as roads)
White - Future roads (same size as current roads, 2 lanes)
Orange - Main highway (goes overtop everything else, 4 lanes)
Box - the base (haven't made it yet)
White circles - entrances to the tunnels.

Red and blue lines are maintenance tunnels that are underneath the road. The white circles are where the entrances/exits to the tunnels are. Red and blue lines connect with each other. Green lines are on the same level as the road and are also above the road, and connect to the main highway in three places, the base in 2, and the main road (by the closed door).

A double white line is a road. It will be the same size as the current roads (2 lanes wide). The Orange lines are the main highway, which is 4 lanes wide.

This is only half the level, the other side will basically be a flipped version of this side.

Also, I think I can take this from a 2 team map to a 4 team map. The intersection of the white lines (there's only one) would be an ideal place to have a base. I would just need to add a few more tunnels to balance the location. I want feedback on this, so tell me what you think.

Also, the white lines were not in my original plan, but it's pretty much the only way to allow vehicles to get onto the main highway. Plus it gives you alot more area to drive in, which is fun.