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

About the report:

The Virginia Department of Transportation (VDOT) began posting deer advisory messages on changeable message signs (CMSs) along a 16.7-mile segment of I-64 between Waynesboro and Charlottesville, Virginia, in October 2015. The posting of these messages during the peak of deer activity, October-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 largely unknown. This study investigated the effectiveness of seasonal deer advisory messages as a DVC mitigation option. Effectiveness was determined by evaluating deer carcass removal data from three October-November deer advisory posting periods. Vehicle speed evaluations were also conducted to determine whether drivers reduced speed in response to the advisories.

For the 16.7-mile section of interstate evaluated, deer carcass removals were significantly lower when deer advisories were posted than when they were not posted, and this difference was statistically significant. During the time deer advisories were posted, there were statistically significant reductions in speeds of up to 2.8 mph at four of the five vehicle sensor stations. Speed reductions were greater when deer advisories were posted during lower traffic volumes.

Given the findings in the study area, seasonal deer advisory messages on an interstate appear to be an effective form of DVC mitigation. The study recommends that deer advisory messages continue to be posted on the CMSs selected in this study and that the number of postings be increased from the current 29% proportion of the days in the posting period to at least a 50% proportion when possible. Posting seasonal deer advisories every other day on the five existing CMSs in this study’s project area is expected to save approximately $595,500 to $1.2 million over the service life of the CMSs. The findings of this study will be shared with appropriate VDOT staff so they may consider posting deer advisory messages on CMSs in areas with high frequencies of deer crashes where appropriate.

Authors