Citation

Zegeer CV, Deen RC, Mayes JG. Transp. Res. Rec. 1981; 806.

Copyright

(Copyright © 1981, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

A study to determine the effect of lane and shoulder widths on accident benefits for rural, two-lane roads and to determine the expected cost-effectiveness of lane and shoulder widening is described. Information concerning geometrics, accidents, and traffic volumes was obtained for more than 25,000 km (15,000 miles) of roads. Run-off-road and opposite-direction accidents were the only accident types found to be associated with narrow lanes and shoulders. Wide lanes had accident rates 10-39 percent lower than those for narrow lanes. Wide shoulders (up to 2.7-m (9-ft) width) were associated with the lower accident rates. Criteria based on a cost-effectiveness approach for selecting highway sections for widening are presented.