Between periods of maintenance, pavement-edge drop-offs can form along the edge of highways. When a driver runs off the roadway, such drop-offs can hinder reentry and may lead to driver overcorrection, loss of control, or overturning on the roadway or roadside. The safety edge is a treatment that is implemented in conjunction with pavement resurfacing and is intended to help minimize drop-off-related crashes.
This report examines the safety effects, costs, and benefits of this low-cost treatment for two-lane and multilane rural highways. The safety research was conducted as an observational before-after evaluation of treated sites using the empirical Bayes method. The economic appraisal consisted of a benefit-cost analysis.
The safety evaluation found that the safety edge treatment appears to have a small positive crash reduction effect. The best effectiveness measure for the safety edge treatment was a 5.7 percent reduction in total crashes on rural two-lane highways. However, this result was not statistically significant. The economic analysis showed that the treatment is very inexpensive and that its application is highly cost-effective for a broad range of conditions on two-lane highways. Inconsistent results were found for rural multilane highways due to a small data sample.