Safety evaluation of STOP AHEAD pavement markings

2008Amjadi, RoyaPDFTech ReportFHWA-HRT-08-043DTFH61-05-D-00024Road markingsUnsignalized intersectionsTraffic safetyHighway planningTurner-Fairbank Highway Research CenterGross, Frank B.Jagannathan, RamanujanPersaud, Bhagwant Naraine, 1947-Lyon, CraigEccles, KimberlyLefler, NancyAmjadi, RoyaVHB/Vanasse Hangen Brustlin, Inc.Persaud Lyon, Inc.United States. Federal Highway Administration. Office of SafetyNTL-OPERATIONS AND TRAFFIC CONTROLS-OPERATIONS AND TRAFFIC CONTROLSNTL-SAFETY AND SECURITY-Highway SafetyFederal Highway AdministrationThe Federal Highway Administration (FHWA) organized a Pooled Fund Study of 26 States to evaluate low-cost safety strategies as part of its strategic highway safety effort. One of the strategies chosen to be evaluated for this study was STOP AHEAD pavement markings. This strategy is intended to reduce the frequency of crashes related to driver unawareness of stop-control at unsignalized intersections. Geometric, traffic, and crash data were obtained at unsignalized intersections for 8 sites in Arkansas, 9 sites in Maryland, and 158 sites in Minnesota. To account for potential selection bias and regression-to-the-mean, an empirical Bayes before-after analysis was conducted to determine the safety effectiveness of installing STOP AHEAD pavement markings. Results of the aggregate analysis indicate a statistically significant reduction in total crashes for Arkansas, Maryland, and the two States combined. The combined aggregate analysis indicates that at least a 15-percent reduction in total crashes can be expected conservatively. There is also a statistically significant reduction in right-angle and rear-end crashes for Arkansas. A reduction in injury crashes is shown for Arkansas and Maryland and is statistically significant at the ten percent level for the two States combined