Trafikulykker, personbilers vægt og kørselsafgifter

Accidents are generally considered one of the mayor social costs associated with car traffic. Traditionally, the marginal external accident cost of car use is calculated without distinguishing between the sizes of different cars. The purpose of the paper is to estimate the importance of vehicle weight for the external accident cost of car use. We follow Anderson and Auffhammer (2013) by estimating the importance of passenger vehicle weight for the risk of being killed or (seriously) injured when a car collision occurs. The analysis is based on data covering all police reported accidents in Denmark in the period 2003-11. The empirical analysis shows that heavy passenger cars are more dangerous to the occupants in other cars and that the marginal external accident cost vary significantly with vehicle size. It is found that a 100 kg increase in car weight increases the probability of a fatality in the other car by 14 pct. over the mean fatality rate. This is in the same range as found by Anderson and Auffhammer using data from US. The derived marginal external accident cost is twice as high for the heaviest passenger cars as compared to the lightest passenger cars. Even though vehicle weight is important for the external accident cost, the location of driving is far more important due to higher accident probabilities in urban areas as compared to rural. For a car of average weight the marginal external accident cost per kilometer is 8 times higher in urban areas as compared to rural areas.