Empirical Study of Driver Responses during the Yellow Signal Phase at Six Maryland Intersections

Abstract

This paper presents the analysis results of driver responses during a yellow phase, based on field observations of 1,123 drivers collected with a specially designed system from six signalized intersections of high crash frequency in Maryland. By classifying drivers into aggressive, conservative, and normal groups based on their responses (i.e., stop or pass) and the distances to the stop line when the signal turns yellow, the statistical tests with the ordered probit model clearly indicate some critical variables and their impacts on a driver’s decision at intersections. Such variables include average traffic flow speeds, traffic volume rate, the green split, the number of through and crossing lanes in the target approach, signal coordination, the difference between a vehicle’s approaching speed and the average traffic flow speeds, a driver’s gender and age, talking over a cell phone or not, a vehicle’s type and model, and so on. The research findings for this study offer the basis for responsible agencies to identify underlying factors contributing to aggressive maneuvers at signalized intersections which often cause traffic crashes, and to develop improvement strategies, such as customized driver education and intelligent safety protection systems.