What do you use for a bridge?

A bridge is a structure built to span a physical obstacle such as a body of water, valley, road or rail, or any other physical obstacle. Bridges are usually constructed for the purpose of providing passage over the obstacle, but they can also be built to resist the passage of an obstacle. The design of a bridge takes into account the function of the bridge, the nature of the terrain where the bridge is constructed, and the materials used to construct the bridge. The choice of materials used to construct a bridge depends on the cost, durability, and strength of the material. Some common materials used to construct bridges include concrete, steel, wood, and stone.