Dedicated to the exchange of ideas among
researchers, professionals, and students and
an informed citizenry since 1958.

Applying the Highway Safety Manual to Two-Lane Road Curves


This paper evaluates the Highway Safety Manual (HSM) crash prediction model using data on twolane rural horizontal curves in North Carolina. An analysis of the local conditions calibration factor for the HSM predictive model in North Carolina found that a large number of sites (approximately 300) are required to meet HSM recommendations. The results showed that annual average daily traffic, curve radius, and curve length were the most important factors in determining crash prediction accuracy, but that average or default values may be used for other parameters with less risk to accuracy.

by Daniel Findley, Charles Zegeer, Carl Sundstrom, Joseph Hummer, and William Rasdorf

Download full article
Download this journal