Effectiveness of Seasonal Deer Advisories on Changeable Message Signs as a Deer Crash Mitigation Tool

Abstract

The Virginia Department of Transportation began posting deer advisory messages on changeable message signs (CMSs) along a 16.7-mi segment of Interstate 64 in October 2015. The posting of these messages during the peak of deer activity, from October to November from 5 p.m. to 9 a.m., was intended to raise driver awareness and reduce the high number of deer–vehicle collisions (DVCs) in the area. The effectiveness of deer advisory messages with regard to DVC reduction is not well known. Effectiveness in this study was determined by evaluating deer carcass removal data from three October and November deer advisory posting periods. Vehicle speed evaluations were also conducted to determine whether drivers reduced speed in response to the advisories. Carcass removals were lower when the deer advisories were posted than when they were not posted, and this difference was statistically significant. During the deer advisory postings, there were statistically significant speed reductions of up to 2.8 mph at four of the five vehicle sensor stations. Speed reductions were greater when deer advisories were posted during periods of lower traffic volumes. Seasonal deer advisory messages on an interstate appear to be an effective form of DVC mitigation. Posting seasonal deer advisories every other day on the five existing CMSs in this study’s project area is expected to save approximately $700,000 to $1.4 million over the service life of the CMSs.