Traffic accidents are a major social problem. Costs for killed and injured in 2005 have been estimated to exceed 29 billions Swedish crowns. To this number should be added considerable human pain. However, the ongoing development as regards traffic safety is positive. During the period 1970 – 2004, the number of killed per year has been reduced to one third, from 1307 to 440 per year, despite the fact that the amount of traffic has more than doubled in this period. This positive development includes unprotected road-users as well as drivers and passengers in vehicles. Furthermore, there are no signs that this positive development should not continue. The present impact analysis demonstrates that research on traffic safety has had great importance for the increase of traffic safety. At the same time, it has formed the basis for considerable commercial success within the automotive industry.