Delta Region Transportation Development Program: Rural Safety Innovation Program Evaluation – Final Report

Final Report

Executive Summary

The Rural Safety Innovation Program (RSIP) is one of several key programs under the United States Department of Transportation's (USDOT) Rural Safety Initiative. The goal of the initiative is to improve safety on rural roads. The objective of this research project was to evaluate the effectiveness of highway safety improvement projects implemented under the Rural Safety Innovation Program – Delta Region Transportation Development Program (RSIP- DRTDP) toward reducing fatalities and injuries on rural roads. Nine agencies implemented a range of safety improvement projects as part of RSIP-DRTDP. Several levels of safety evaluations were performed as part of this research. Three projects were selected for detailed quantitative evaluation. One project lent itself to a simpler quantitative analysis, and two projects were more suited to a qualitative, rather than quantitative, analysis, focusing on lessons learned by the agencies during implementation. Three projects were not included in the evaluation due to insufficient data and/or the ability to link the necessary data for analysis purposes.

Many of the safety improvement projects implemented as part of the RSIP-DRTDP were able to achieve the overall goal of the Rural Safety Initiative of improving safety on rural highways. In Mississippi (RSIP Project 27), installation of centerline rumble strips on rural two-lane roads, where shoulder rumble strips were already present, resulted in a decrease in single vehicle run- off-road (SVROR), sideswipe-opposite direction, and head-on crashes. The dual application of centerline and shoulder rumble strips on rural two-lane roads resulted in a 35-percent reduction (SE=10.5) in total target crashes and a 40-percent reduction (SE=12.3) in fatal and all injury (FI) target crashes. In Louisiana (RSIP Project 37), improved signing and pavement markings at rural stop-controlled intersections reduced total and FI intersection and intersection-related crashes. The improved signing and pavement marking treatments resulted in crash reductions between 30- and 67-percent at stop-controlled intersections on rural two-lane roads. In Arkansas (RSIP Project 33), the safety evaluation of cable median barrier installed on rural interstates indicated a 49-percent reduction in fatal and serious injury (FS) crashes that was marginally significant at the 88-percent confidence level.

Lessons learned in Tennessee (RSIP Project 25) and Missouri (RSIP Project 32) in developing a sign inventory system and installing dynamic message signs and closed-circuit video, respectively, will also benefit other agencies interested in implementing similar programs. From a qualitative perspective, the RSIP projects implemented in Tennessee and Missouri were a success and benefitted the respective highway agency.

For the RSIP projects for which the safety evaluation yielded unreliable estimates (RSIP Project 36) or the safety effectiveness could not be completed due to insufficient data (RSIP Projects 28, 31, and 34), there is insufficient evidence at this time to reliably determine treatment effectiveness.

The knowledge gained from the evaluation of the RSIP-DRTDP projects can benefit other highway agencies when making funding decisions concerning future safety improvement projects and programs.