Pedestrian Countdown Timers: Do Drivers Use Them to Increase Safety or to Increase Risk Taking?
Transportation Research Board Business Office
500 Fifth Street, NW
Pedestrian countdown timers (CDTs) are promoted as a means of improving pedestrian safety at intersections. However, there are concerns that drivers view the timers while approaching the intersection and use the information to drive more aggressively - an unintended consequence that may have adverse safety impacts. Pedestrian CDTs have been in widespread use in Lawrence, Kansas for 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 without. Continuous speed data were collected on approaching traffic and analyzed to determine if there were changes in speed between 400 ft (121.92 m) 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) were recorded. Analysis revealed that drivers were significantly less likely to increase their speed in order to reach the intersection before the beginning of the red phase when CDTs were present, and 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.
Monograph Accession #:
Transportation Research Board
500 Fifth Street, NW
Schrock, Steven D
Transportation Research Board 87th Annual Meeting
Figures (4) ; References (8) ; Tables (3)
Administration and Management; Highways; Operations and Traffic Management; Safety and Human Factors; I83: Accidents and the Human Factor
Transportation Research Board Annual Meeting 2008 Paper #08-2203
Jan 29 2008 4:33PM