Culvert wildlife crossings allow passage for wildlife to cross under roadways, railways, and embankments and can improve safety for the motoring public. These crossings utilize pipe or box culverts and are similar to underpass crossings, allowing movement beneath the roadway. These crossings can be designed in areas without water flow or at existing culvert crossings with water flow.

These types of wildlife crossing structures can be sized and located through coordination by the roadway designers with the District Environmental Coordinator and the ENV Division. Details can be obtained from the ENV Natural Resource Management Section and District Environmental Coordinators. When preparing structure plan sheets for cast-in-place or precast box culverts, designers should note that these culverts can have single or multiple openings allowing the passage of water, livestock, or wildlife under a roadway.

These crossings make use of culvert structures to provide wildlife passage underneath a roadway. Box culverts or pipes can be used depending on the specific needs of the project as shown in . Sizing of the crossing should be based on the wildlife intended to use the crossing. Refer to for additional information.

These crossings incorporate box culverts and pipes to allow both wildlife and water to cross underneath the roadway as shown in . The crossing should be sized based on hydraulic data and capacity requirements as well as on the size of the animals which will use the crossing. These crossings may also include dry walkways (1-ft to 2-ft high and 1.5-ft to 2-ft wide) within the culvert to allow wildlife easier passage through the structure. Refer to for additional information.

In some cases, culvert crossings may need to accommodate fish or other aquatic organisms. To facilitate passage for these types of organisms, lower hydraulic velocities and culvert slopes should be considered.