Abstract
The direct losses caused by traffic congestion on the Dutch main road network in 1995 are calculated. The costs caused of slowing down by traffic, but no stand still, are also estimated. The estimated direct costs of traffic congestion concern the extra fuel consumption and the costs of waiting time by drivers and passengers. Costs related to the environment and traffic safety are not taken into account. The costs are calculated on amply 630 million Dutch guilders. If the costs of slowing down are also considered, the damage is more than 1.5 thousand million Dutch guilders.