Effects of Countdown Timer on Yellow Light Running: An Empirical Study

Abstract

Yellow light violation is exacerbated by the deficiency in the definition of yellow light function from Chinese road traffic safety law and no penalty to such violators. Last January, the embarrassment of a new traffic regulation pertaining to deter drivers from running yellow light made countdown timer be the better option to prevent this risky behavior. Since then, more and more countdown timers have been installed in China cities. However, the actual influences on yellow light running of countdown timer are still unclear, though there are very few relevant studies. The current study attempts to uncover more deeply the effects on yellow light running of countdown timer. Data on the number of yellow light running occurrence, entry time, and entry speed of vehicles crossing the stop line after yellow light onset were collected at four comparable intersection approaches located in Harbin, China. Statistical analysis results show that countdown timer has limited positively impact on the reduction of yellow light running, but no significant effect on entry speed. Furthermore, countdown timer leads to increase entrance into the intersection during the earlier portions of yellow signal.