Projects - Reducing Roadkill AFocus on Mule Deer and Golden Eagles in WyomingReducing Wildlife-Vehicle Collisions in Wyoming

Research Associate: Corinna Riginos

Project overview: Assessing the effectiveness of measures aimed at reducing wildlife-vehicle collisions in Wyoming

Backstory: Every year, there are an estimated 1-2 million wildlife-vehicle collisions across the US every year. Up to 50% of collisions may not be recorded because the hit animals leave the road or right-of-way before dying. In Wyoming alone, the direct costs of wildlife-vehicle collisions total nearly $50 million per year between injury/damage costs and lost wildlife value. Wildlife-vehicle collisions negatively impact wildlife by reducing their populations and impeding their movement as roads can cross migratory routes, especially mule deer which are the majority of animals impacted by wildlife-vehicle collisions in Wyoming.

Corinna and her team are identifying traffic volumes above which deer struggle to cross roads. This will be used to help Wyoming Department of Transportation (WYDOT) identify priority areas for crossing structures (highway under- and over-passes). She is also working with WYDOT to assess the effectiveness of reduced night-time speed limits as a method to decrease wildlife-vehicle collisions. Reduced speed allows more time for drivers to react, is inexpensive to execute and can be completed on a short timeline. The study showed that reducing night-time speed had no reduction on the number of wildlife-vehicle collisions and is not an effective measure on high speed, rural, two lane highways. 

Finally, with support from the National Fish and Wildlife Foundation (NFWF), she is working to determine where deer migration corridors and winter use areas are most threatened by vehicle collisions; this will further guide priority locations for deer-vehicle collision mitigation measures. She will also determine where Golden Eagles are most likely to scavenge on deer carcasses and, in doing so, get hit by cars. This will help planners to prioritize areas for frequent deer carcass removal and/or measures to reduce deer-vehicle collisions.

For more information, please visit Corinna’s website at:

Current Status: Project is complete. 

Project Partners: Wyoming Department of Transportation, National Fish and Wildlife Foundation 

Project start year: 

Location: Wyoming