An examination of the impact of five grade-crossing safety factors on driver decision making

Abstract

ABSTRACTThe authors applied signal detection theory to model the impact of five grade-crossing safety factors to understand their impact on driver decision making. The safety factors were improving commercial motor vehicle (CMV) driver safety through federal regulations, increasing locomotive conspicuity with alerting lights, increasing locomotive conspicuity with reflectors, increasing sight lines, and improving warning device reliability. The authors estimated sensitivity and bias for eight warning devices associated with each safety factor. The authors also calculated the proportion of variance accounted for by each safety factor and device type to examine the reliability of each on grade-crossing safety. Driver decision making improved due to the warning device type and the introduction of the safety factor. Of the two, warning devices exerted the most impact because they encouraged drivers to stop at grade crossings. Regulations to improve CMV driver safety, alerting lights, sight lines, and reflectors were generally equally effective in improving grade-crossing safety. A comparison of the results from the descriptive model to that produced by a more traditional accident analysis suggest that examination of accident frequency alone may minimize the impact of important safety factors and emphasizes the need to consider accident frequency with respect to human behavioral metrics.