Abstract
Traffic accidents occurred before and after sunset in Chiba was analyzed. It was found that the rate of traffic accidents before and after sunset was higher than that of any other times. The rate of fatal accidents during twilight time is much higher than that of any other time, because many fatal pedestrian accidents had occurred during twilight time. But many vehicle headlights during twilight time turned on. Drivers of first vehicle concerned were adversely affected by sun glare, when the sun is located in front of vehicle.
