Bridge Types

Here is a list of bridge types.

All costs are in the year 1960, for a six tile bridge. (Or when it comes out, or min/max size)

Wooden
Wooden Bridges are cheap and are the first bridges to come out. they can span a good distance. However, they have a very low speed limit forcing all vehicles to slow down. It is highly recommended that you replace them as soon as possible, to increase efficiency.

Concrete
Concrete bridges may be a slight improvement of the Wooden Bridge, but they are still pretty useless. They don't have a long range, and only increases the max speed by a little. Only build if you're into the looks of the bridge, or if you're short on money. Replace as soon as possible.

Steel Girder
Steel Girder Bridges are a slight upgrade of the Concrete Bridge. It has a higher speed capacity than the previous two (but is still pretty slow) and can reach farther than the Concrete Bridge. A lower end bridge that may suffice if you're looking for a cheap, but a somewhat fast bridge for Road Vehicles.

Concrete Suspension
Concrete Suspension Bridges has a longer length than some of the previous ones.