TRENDS AND UNCERTAINTY IN AIR POLLUTION IMPACTS AND EXTERNAL COSTS OF BELGIAN PASSENGER CAR TRAFFIC

The main objective of this paper is to track the changing importance of air pollution impacts by Belgian passenger cars. Our assessment of environmental impacts is based on the calculation of external costs with the ExternE methodology. Our results show that the decline of air pollution impacts from Belgian passenger cars between 1993 and 1998 was limited. This is explained by the combination of three contributing factors the slow turnover of the fleet, the typical Belgian high and growing percentage of diesel fuelled passenger cars and the annual increase of the average mileage per car. The secondary objective is to investigate to what degree the choice of emission factors influences our conclusions. Although estimates of the overall cost of air pollution derived from MEET and Infras are similar, the trend towards improved air quality is more pronounced for MEET.