7: Assessment of External Costs: How and Why?

This chapter first lists the various externalities generated by transport emphasising the importance of transport nuisances assessment and monetarisation. It further presents the general methods of valuing externalities, direct methods of costs of damages and indirect methods of willingness to pay or to receive, that is “revealed preference methods” based on surrogate markets and “stated preference methods” based on surveys. For each external effect, the valuation approaches used are described. The results of various studies made in Europe in this field are compared.

When a car moves in the streets of one of our cities, it makes noise and generates vibrations, emits gases and particles and becomes a hazard for pedestrians, cyclists and other motor vehicles. The construction, maintenance and future end-of-life of the car produce many industrial wastes and the production of petrol or diesel is also a source of pollution. Cars slow one another down, thus each car causes other cars to incur extra travel time. The effects of traffic congestions in urban areas are experienced every day.