车辆在有倒计时的信号控制交叉口上"抢绿灯"的安全隐患其实在于未正确设置交叉口绿灯间隔时间,并不在于倒计时本身。通过理论推导与分析,建立了有倒计时条件下信号控制交叉口绿灯间隔时间的计算模型。研究认为,驾驶员在有倒计时的信号控制交叉口上的驾驶行为发生变化,有倒计时的信号控制交叉口上不存在"两难区",原来根据"两难区"确定绿灯间隔时间的方法并不适用于有信号倒计时的情形,有倒计时的信号控制交叉口的绿灯间隔时间应该全部作为全红时间。算例分析表明,有倒计时的信号控制交叉口的全红时间随着计算车速增加而减少,但不少于3 s。
The safety risk of drivers' " rushing green light" behaviors at a signalized intersection with countdown indication comes not from the indication itself, but from wrong configuration of the inter-green interval. Configuration of the inter-green interval at a signalized intersection with countdown indication is studied, and a model is derived to calculate it through the theoretical derivation and analysis method. The study reveals that driving behaviors at a signalized intersection with countdown indication are totally different from those at a signalized intersection without countdown indication, and that the dilemma zone does not exist at a signalized intersection with countdown indication. Hence configuration of the inter-green interval according to "dilemma zone" is not suitable for a signalized intersection with countdown indication, the entire inter-green interval should be indicated as an all-red period, and the calculation example shows that the duration of the all-red period decreases as the calculated speed increases, but it is always more than 3 s.