The external accident cost of road use is a function of the marginal relationship between road use and accidents, as expressed, for instance, by the elasticity. This elasticity is, however, not necessarily constant, but may be assumed to depend on the traffic volume as seen in relation to road...

Background: There is comprehensive evidence of the positive health effects of physical activity, and transport authorities can enable this by developing infrastructure for cycling and walking. In particular, cycling to work or to school can be a relatively high intensity activity that by itself...