Interchange as the main factor determining wildlife–vehicle collision hotspots on the fenced highways: spatial analysis and applications

Despite the fact that all highways in Hungary are built with fencing, there are still 5 % of traffic accidents that involve wildlife. Therefore, this study focused on the incidence of collisions along fenced roads. Wildlife–vehicle collision (WVC) hotspots were mapped, and the spatial frequencies were analysed with Poisson regression. In general, most WVCs and almost all of the roe deer fatalities occurred at highway intersections, or at interchanges. Red fox casualties also occurred at interchanges as well as at passages. Wild boar fatalities were not particularly frequent at interchanges but were recorded near railways that are parallel to highways; otter–vehicle collision hotspots were found near their habitats and migration corridors such as streams. For otter, badger and wild boar, we were able to examine the role of local population density; most WVCs happened in areas of high population density. The badger model predicted that badger kills were more likely where the fence was not buried in the soil. Most WVCs occur at interchanges because wildlife enters the right-of-way (ROW) at fence ends; or it enters at a fence gap and runs along the outside of fence and becomes funnelled onto the ROW at the interchanges. Interruption in the continuity and linearity are important factors in both cases. We concluded that the number of WVCs can be reduced significantly if animals were prevented from entering highway interchanges and proposals for mitigation were made. We also propose a tool to assist in alleviating WVCs, by mapping them in Google Maps and integrating hotspots into a car navigation system.