Pilot Evaluation of the Use of Contract Towing and First Responder Strategies in the Virginia Department of Transportation’s Staunton District

About the report:

This study evaluated the contract towing and first responder pilot projects in the Virginia Department of Transportation’s Staunton District. The evaluation included before and after studies of incident duration and comparisons of clearance time. Both pilots were operational simultaneously during the period from May 1 to October 31, 2016, on I-81 from mile marker 264 in Shenandoah County to mile marker 302, including the I-81/I-66 interchange in Frederick and Warren counties. The first responder initiative was also piloted within this segment of I-81 during the period from August 1 to October 31, 2015.

I-81 in Shenandoah County was chosen for the pilots based on historical incident data and the number of incidents involving heavy vehicles with lane blockage. The purpose of the study was to evaluate before and after data to determine the effectiveness of each pilot separately. For the contract towing pilot, the evaluation analyzed lane clearance, incident duration, traffic impacts, and benefit-cost ratios. For the first responder pilot, the evaluation analyzed lane clearance, incident duration, and benefit-cost ratios. In addition, stakeholder interviews were conducted to document qualitative assessments and lessons learned.

The results indicated that contract towing operations reduced average lane clearance time, queue dissipation time, and user delay costs while increasing average incident duration and regain time. Conclusions regarding the effectiveness of the contract towing pilot could not be determined because all results were statistically insignificant because of the small sample sizes. First responder operations resulted in statistically significant reductions in average lane clearance time (10.58 minutes at α = 0.05) and incident duration (7.75 minutes at α = 0.10), thereby providing conclusive evidence of the effectiveness of the first responder pilot.

The study recommends that opportunities be explored to continue with the first responder program in the Staunton District and expand the program to other districts of the Virginia Department of Transportation. Opportunities should also be explored for targeted deployment of contract towing operations.

Authors