Indikatoren zur Erfassung von sozialen Kosten und Nutzen des Verkehrs: Möglichkeiten und Grenzen.

If it is assumed that the external impacts of traffic have increased approximately in proportion with traffic levels, they can be taken to have multiplied about sevenfold over the last 40 years. Besides this quantitative aspect, there has also been a qualitative change in the political understanding of general welfare and economic benefits, which means that greater and methodologically superior assessment of social costs and benefits has become an essential feature of traffic policy decision making.