Culvert is a structure constructed over running water or physical obstruction. The main purpose of constructing culvert structure is to provide passage over the obstruction. 

Slab culvert, a type of culvert, could be three-sided or simply a deck slab. It is embedded in the soil on both sides. The slab provides a bridge over the distance. Slab culverts can replace box culverts if no artificial flooring is necessary.

Slab/Bridge-culvert

Slab culverts do not have bottom slabs, therefore, the natural flow of water is maintained and natural bottom substrate remains intact. The safety of high-velocity vehicles is not affected by slab culvert as it doesn't have any sharp corner. 

While constructing the slab culvert, a series of slabs are laid to form the bridge-like structure. After that, a pavement surface is placed on top to serve the purpose as the road.

The standard span length ranges from 8’ to 48'. ASTM C 1504 design code is followed to design the slab culvert.