Box girder bridge
| Ancestor | Tubular bridge | 
|---|---|
| Related | jetway, skyway | 
| Descendant | segmental bridge | 
| Carries | Pedestrians, automobiles, trucks, light rail, heavy rail | 
| Span range | Medium | 
| Material | Steel, reinforced concrete, prestressed concrete | 
| Movable | Possible | 
| Design effort | High | 
| Falsework required | Yes, if cast-in-place reinforced or prestressed concrete is used, which is typical for freeway overpasses | 
A box girder bridge, or box section bridge, is a bridge in which the main beams comprise girders in the shape of a hollow box. The box girder normally comprises prestressed concrete, structural steel, or a composite of steel and reinforced concrete. The box is typically rectangular or trapezoidal in cross-section. Box girder bridges are commonly used for highway flyovers and for modern elevated structures of light rail transport. Although the box girder bridge is normally a form of beam bridge, box girders may also be used on cable-stayed and other bridges.