An Evaluation of Shoulder Rumble Strips in Montana

https://doi.org/10.21949/15181872003Final report; Mar. 2001-Dec. 2002.PDFTech ReportFHWA/MT-03-008/81578157Rumble stripsRoad markingsTraffic control devicesHighway traffic controlRoad shouldersParts of roadsRoadsRollover crashesCollisionsTraffic crashesHighway safetyBenefit cost analysisRumble stripsRoad markingsTraffic control devicesHighway traffic controlRoad shouldersParts of roadsRoadsRollover accidentsCollisionsTraffic accidentsHighway safetyBenefit cost analysisMontanaMarvin & AssociatesMontana. Dept. of Transportation. Research Section.Marvin, Robert R.Clark, D. J.Marvin & AssociatesMontana. Dept. of Transportation. Research SectionUnited States. Federal Highway AdministrationNTL-OPERATIONS AND TRAFFIC CONTROLS-Traffic Control DevicesNTL-SAFETY AND SECURITY-Highway SafetyNTL-SAFETY AND SECURITY-AccidentsAn evaluation of shoulder rumble strip's effectiveness in reducing off-road and rollover crashes on Montana's highway system utilized 10 years of crash data on 393 miles of Interstate Highways and 213 miles of National Highway System (NHS) and Primary Highways. Statistical analysis of crash data involved rumble strip segments and control segments without rumble strips for 3 year periods before and after implementation of shoulder rumble strips. Descriptive statistics were developed from global data sets and comparative statistics on equivalent segments produced a finding of significant crash reductions on Interstate Highways, while the effect of shoulder rumble strips on NHS and Primary Highways was uncertain due to an inadequate sample size. Analysis of contingency tables indicate that the reduction in Interstate off-road crash rates attributable to shoulder rumble strips was 14.0% with a corresponding reduction of 23.5% in severity rates. The benefit/cost ratio for construction of shoulder rumble strips on Interstate highways was 19.5. A shoulder rumble strip driver survey involving questions related to knowledge of rumble strips, frequency of encounters, reaction to exposure, and general opinions on their use was incorporated as part of the study. The survey indicated that 95% of the driving public was familiar with rumble strips and their use with the majority of drivers encountering rumble strips on every highway trip. The overwhelming majority of motorists liked the benefits that shoulder rumble strips provide.88