Impact of countdown timer on driving maneuvers after the yellow onset at signalized intersections: An empirical study in Changsha, China

This study investigates the impact of countdown timer on driving maneuvers after the onset of yellow at signalized intersections in China. Signal phasing and traffic operations were videotaped at four comparable intersections under normal conditions in Changsha city, China. Microscopic details were extracted to yield 24 h worth of data including the onset time of yellow, the onset of red, vehicle location, and maneuvers after the onset of yellow. The difference in driver’s stop/go decisions at the countdown and non-countdown timer installed intersections were investigated with binary-logistical regression analysis. By classifying the driving population into several distinct groups, this study further investigates the correlation between the countdown timer and two hazardous maneuvers: aggressive acceleration and conservative (abrupt) stopping, respectively. The descriptive results, though preliminary, indicate that the countdown timer can better assist drivers in their decision-making process and thus may reduce hazardous driving maneuvers during the phase transition period.

► We study the impact of countdown timer on driving maneuvers. ► Driving population is classified into three distinct groups. ► Statistical analyses of the impact on hazardous driving maneuvers are performed. ► Results can better assist traffic engineers in deploying countdown timers.