Sketch of the Bridge

Bridges are structures designed to cross ravines or obstacles such as rivers, railways or highways. Bridges are built for pedestrian crossings, vehicles or trains over obstacles. Bridges are also part of a land transportation infrastructure that is vital in traffic flows. The bridge is often a critical component of a road segment, as it determines the maximum load of vehicles passing through the road.

A bridge is usually designed the same for trains, for road guides or for pedestrians. There are also bridges built for large pipes and waterways that can be used to carry goods. Sometimes, there are limits to the use of bridges; for example, there are bridges that are suspended for highways and should not be used by pedestrians or cyclists. There are also bridges built for pedestrians (pedestrian bridges), and may be used for cyclists.
The design and the material of the bridge construction depends on the location and also the type of cargo that will be borne.