Safety Evaluation of Profiled Thermoplastic Pavement Markings

The Development of Crash Modification Factors (CMFs) program conducted safety evaluation of profiled thermoplastic pavement markings for the Evaluation of Low-Cost Safety Improvements Pooled Fund Study. This study evaluated application of profiled thermoplastic pavement markings. This strategy involves upgrading existing markings from flat-line thermoplastic or other standard markings to the profiled product. These profiled markings are designed to provide an improved level of vision to drivers, particularly during wet-road surface conditions. Geometric, traffic, and crash data were obtained for two-lane and multilane road sections in Florida and South Carolina where the treatment was applied to the edge lines. To account for potential selection bias related to regression-to-the-mean, an empirical Bayes before–after analysis was conducted. The analysis controlled for changes in traffic volumes over time and time trends in crash counts unrelated to the treatment. Intersection-related, snow/slush/ice, and animal crashes were excluded from the analysis. Only nighttime wet-road crashes, a principal target crash type, exhibited a material change—an estimated CMF of 0.908. Although the estimated CMF was based on a small sample of crashes and was not statistically significant at the 95-percent confidence level, it was consistent between the two States, which suggests that its use might be justifiable. The benefit–cost ratio for flat-line thermoplastic markings was 3.65:1 based on the consistent reduction in nighttime wet-road crashes and estimated with conservative cost and service life assumptions. Applying the sensitivity analysis recommended by the U.S. Department of Transportation, this value could range from 2.01:1 to 5.04:1. These results suggest that the treatment—even with conservative assumptions on cost, service life, and the value of a statistical life—can be applied cost effectively despite the relatively small crash reduction effects.

The full reportis available at https://www.fhwa.dot.gov/publications/research/safety/17075/17075.pdf