Crash Reduction Factors for Deer-Vehicle Crash Countermeasures

Abstract

A detailed critical evaluation of deer–vehicle crash (DVC) countermeasure safety analyses was completed during the past 3 years. Previous summaries of this literature did not focus on the adequacy or rigor of these analyses and generally repeated recommendations or based them on the exaggerated and sometimes incorrect safety impact conclusions presented in past documents. A comparison of past safety analysis designs and documentation with generally accepted transportation safety research standards was completed for 16 potential DVC countermeasures. The countermeasures were grouped into one classification system on the basis of the general safety result trends of past research and another system that used categories defined for the safety strategies used in the implementation of the AASHTO Strategic Highway Safety Plan. All but two of the DVC countermeasures were grouped into the AASHTO categories of “tried” and “experimental.” The proper implementation of wildlife fencing and crossings consistently resulted in DVC reductions, and these were categorized as proven strategies. The majority of the DVC countermeasures reviewed are used in the field, but their actual safety impact had rarely or never been studied. The study of other countermeasures produced conflicting safety analysis results. The use of past research results to develop valid DVC countermeasure crash reduction factors is not considered advisable given the safety analysis approaches used and the results produced. Research needs for the countermeasure categories are suggested to guide the activities needed to achieve this goal.