The study reported herein was initiated to investigate the effects of Interstate geometrics on the accident experience of the Interstate System. The analysis showed that there is a difference in the accident experience of the various interchange configurations studied. On between-interchange units, which account for one-third of the accidents, the existence of delineators, paved right shoulders bituminous surfacing and increased minimum stopping sight distance reducer accidents. On interchange units which account for two-third of the accidents, paved right shoulders increased minimum stopping sight distance, and the existence of delineators can reduce accidents where as other variables showed mixed effects. Use of the mathematical models developed can provide estimates of the average number of accidents.
Abstract