Empirical analysis of countdown signals on pedestrian behaviour

The installation of countdown pedestrian signal display at signalised intersections was proposed as part of an overall strategy for improving pedestrian safety, especially at such intersections. Based on field observations of critical pedestrian-related parameters at five similar intersections (three with countdown signals and two without countdown signals) in Shanghai, this research evaluated the impact of countdown signals on intersection safety and efficiency. Three categories of data were collected using a video detection system and questionnaire methods – crossing behaviour data (e.g. pedestrian speed and number of pedestrians obeying signals), questionnaire data (e.g. understanding of countdown signals) and crosswalk-related data (e.g. cycle length and length of the crosswalk). Statistical analysis results based on t-tests and analysis of variance revealed that the impacts of countdown signals on older and younger people are different in terms of compliance ratio and successful crossing ratio. Countdown signals also decreases the perception–reaction time and significantly improves crossing speed, especially at the end of clearance time. The questionnaire results showed that understanding of the real meaning of pedestrian clearance time is not changed by the installation of countdown signals. Despite its effectiveness in facilitating the pedestrian decision-making process, the installation of countdown signals may adversely increase the possibility of collisions with unexpected right-turning vehicles, crossing vehicles or bicycles due to the significantly increased speeds of pedestrians at the end of clearance time.