Strategies for Ungulate-Vehicle Collision Mitigation

Abstract

Wildlife mortality caused by vehicles presents a serious conservation and economic problem, as collisions with large mammals are global, pervasive, and increasing. The combination of increasing ungulate populations combined with increasing vehicle-miles traveled has heightened the significance of this problem. We reviewed the U.S. and, secondarily, European scientific literature pertinent to mitigating the effects of ungulate-vehicle collisions. This review presents an analysis of ungulate movement and behavior in relation to roads to further develop general conclusions about accurately locating high frequency collision areas. Some successes in reducing ungulate-vehicle collisions have been documented with fencing, modified fencing, and grade separation via crossing structures, although traditional solutions often are expensive, e.g., fencing, overpasses, have limited effectiveness, e.g., reflectors, static warning signs, or may further habitat fragmentation or create barriers to movement, e.g., ungulate-proof fencing, vegetation clear-zones. We also present several case studies illustrating animal-detection driver-warning systems, technology based deployments, applied to the problem of ungulate-vehicle collisions. Although there is significant interest and potential in animal-detection driver-warning systems, many technical issues must be addressed before they are ready for general use. We emphasize the need for more sound statistical design in determining efficacy of treatments.