Road safety is the result of measures to reduce therisk of accident and injury. (Nationalencyklopedin,2008). In principle, road safety means to arrive saveand sound.Safe traffic in cities is mainly achieved throughappropriate speed. In Sweden, more than half ofall rides happen with a speed above the legal speedlimit (Holmberg, Hydén m.fl, 1996). To reducespeed in order to increase safety requires measureswhich influence a driver?s motives for his orher choice of speed even if these are not rational(Boverket, 2002).