倒计时信号灯对交叉口交通安全影响研究

针对倒计时装置对信号交叉口交通安全的影响进了研究。采集了9个信号交叉口共计13个进口道的相关数据,以红黄灯时段车辆通过停车线情况及交通冲突数作为替代安全评价指标,对比设置及未设置信号倒计时装置的交叉口进口道数据,量化了信号倒计时装置对城市信号交叉口交通安全的影响。结果表明,在交叉口直行和左转2个方向上,受到信号倒计时装置影响,车辆在交叉口进口道处的冒险通行频次以及交通冲突数均有显著提升,对交叉口交通安全水平存在负面影响,建议在工程应用中谨慎使用信号倒计时装置。 

Evaluating Safety Impact of Countdown Signal Timers at Signalized Intersections

The primary objective of this study is to evaluate the impact of countdown signal timers on the safety of signalized intersections .Data were collected at 13 approaches of 9 signalized intersections .A cross-sectional analysis was conducted to compare the safety performance of signalized intersections with and without countdown timers .Various sur-rogate safety measures ,such as the red-yellow running violation ratio and traffic conflicts ,were used for safety assess-ment .It is found out that the countdown signal timers significantly increase the red-yellow running violation and traffic conflicts at signalized intersections for both through and protected left-turn movements .The study results of this paper suggest that the countdown signal timers negatively affect the safety performance of the signalized intersections and there-fore ,should be used more cautiously .