Information and traffic accidents

From the Freakonomics blog we learn of an interesting experiment to do with traffic accidents at intersections. Freakonomics reports on a story they received from Jeffrey Mindich, a senior news anchor at International Community Radio in Taipei. Mindich wrote,

About a year ago in Taiwan, they started installing countdown timers at traffic lights at a number of intersections. Some counted down the amount of time remaining 'till a green light turned yellow and then red, while others counted down the amount of time remaining before a red light turned green. Some intersections had both. .... Ostensibly, the reason for the timers was to give people more precise information about exactly how much time they had remaining before the light changed, in the hope of reducing accidents.

The results,

A research institute within Taiwan’s Ministry of Transportation released a report showing that at 187 intersections which had the timers installed, those that counted down the remaining time on green lights saw a doubling in the number of reported accidents, with a 33 percent increase in the number of injuries, while those that counted down until a red light turned green saw a halving in both the number of reported accidents and injuries. Intersection that had both red and green light timers saw a 19 percent increase in reported accidents and a 23 percent increase in injuries.