Abstract
An attempt is made to study how drivers react to speedlimits. The speed behaviour of two groups of drivers was studied simultaneously on a stretch of highway near Vienna on which there were no distracting road signs, ascents or descents and no entry or exit points Two experimental groups drove under speed limits of 80 km and 100 km per hour. Two corresponding control groups were free from any speed restriction. The drivers ' response to two different speed limits both at daytime and during the night are recorded.