Targeting mitigation efforts: The role of speed limit and road edge clearance for deer–vehicle collisions

Abstract

ABSTRACTDeer–vehicle collisions (DVCs) have major social, economic, and animal welfare costs. Modeling of accident risk relative to environmental characteristics could enable managers to plan the layout of new roads or determine optimal location of mitigation measures to reduce the number of accidents on existing roads. We analyzed position data providing road crossings from 67 global positioning system (GPS)‐marked red deer (Cervus elaphus) and location data of 271 car killed deer within the home ranges of the GPS‐marked red deer. We modeled collision risk as a function of speed limit, season, road characteristics, and habitat features. For a subset of the data, we tested if vegetation clearance along a highway reduced the collision frequency of red deer. The relative risk for DVCs increased with speed limit. We found a higher risk for DVCs during winter compared to the other seasons. Forest cover, distance to pasture, and terrain ruggedness substantially affected risk of DVCs. Road edge clearance reduced the frequency of DVCs, but the effect appeared in the winter season only with a decrease of 53%. Our study highlights that speed limit reduction and road edge clearance are both powerful mitigation tools to reduce the number of DVCs. © 2014 The Wildlife Society.