Citation

Cleveland DE, Kitamura R. Transp. Res. Rec. 1978; 681: 53-62.

Copyright

(Copyright © 1978, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

A macroscopic study of off-road accident, road, and traffic flow characteristics on the rural two-lane state trunkline system was made to assist the Michigan Department of State Highways and Transportation (MDSHT) in developing priority programs for roadside hazard improvement. Statewide accident data for the period between 1971 and 1974 were analyzed, and, based on these data, a macroscopic modeling effort was undertaken for two-hundered and seventy 3.2-km (2-mile) sections of homogeneous two-lane road that had widely varying road and traffic conditions. Road data came primarily from analysis of MDSHT photolog files. Multiplicative models for different groups of average daily traffic were developed in which restriction on passing-sight distance, number and length of curves, and length of road were found to be the main explanatory variables. These models, which were evolved dynamically with the aid of statistical computer programs, were tested for the validity of underlying assumptions and were shown to explain as much of the variance as would be expected assuming a Poisson process of accident frequency. The models were validated by using additional data for two cases of low average daily traffic, and satisfactory results were obtained. Several immediate uses for the models are presented.