Modification of Driver Behavior Based on Information from Pedestrian Countdown Timers

Abstract

Pedestrian countdown timers (CDTs) are promoted as a means of improving pedestrian safety at intersections. However, there are concerns that drivers view the CDTs when approaching the intersection and use that information to drive more aggressively - an unintended consequence that is detrimental to safety. Pedestrian CDTs have been in use in Lawrence, Kansas for at least three years, and so any novelty effect should have passed, allowing for an accurate analysis of the long-term effects of the devices on traffic. Four intersections along an arterial corridor in Lawrence were studied - two with CDTs and two with flashing hand pedestrian signal heads. Continuous speed data were collected on approaching traffic and analyzed to determine if there were changes in speed between 400 ft upstream from the intersection (the point when the CDT information could be read by drivers) and the intersection stop bar. Additionally, the ultimate decision of the drivers (whether they stopped or not) was recorded. Analysis revealed that drivers were less likely to increase their approach speed when a CDT was present. Additionally, some drivers began to slow to a stop before the beginning of the amber phase when CDTs were present. These findings indicate that drivers use the information provided from pedestrian CDTs to improve their driving decisions. Even though the CDT information was not intended to be used by drivers, it appears that they are indeed doing so in a way that results in safer driving actions.