Display of required crossing speed improves pedestrian judgment of crossing possibility at clearance phase

At crosswalks with countdown timers, pedestrians arriving at the clearance phase tend to start crossing when the remaining time is too short. It is unclear whether this phenomenon is due to errors in judging the possibility to finish crossing before signal lights turning red. This study evaluated and compared pedestrians' accuracy in judgment of crossing possibility based on two cues: the amount of remaining time, and the minimum required speed to finish crossing within clearance phase (road width / remaining time). The results showed that pedestrians overestimated crossing possibility when they made judgments based on remaining time, especially when the road was narrow. By contrast, the display of required speed resulted in higher overall accuracy and lower false alarm rate, due to higher sensitivity to different crossing possibilities and more conservative set of response criterion. This advantage is consistent across different road widths. These findings suggest that pedestrians' risky decisions based on the countdown timers are partly induced by overestimation of crossing possibilities. The advantages of required-speed display over traditional countdown timers indicate a strong possibility to improve pedestrian judgments by information design.