Evaluation of wide edgelines on two-lane rural roads

The effect of 8-in.-wide edgelines on the incidence of run-off-the-road (ROR) and related accidents was evaluated. The treatment locations consisted of three two-lane rural road sections totalling 60.7 miles. A before-and-after design with a comparison group and a check for comparability was used to analyze data. Five years of accident data, covering the 3 years before wide edgeline installation and the 2 years after installation, were used. It was concluded that there is no evidence to indicate that wide edgelines significantly affected the incidence of ROR and related accidents for any individual treatment location or for the locations combined. The related accidents include ROR accidents that involved driving under the influence of alcohol or drugs, ROR accidents on curves, ROR accidents during darkness, and opposite-direction accidents.