Table 3 presents the resulting marginal external congestion costs for the reference situ-
ation in 2005*. The marginal external cost are very high, especially in the peak period.
The main explanation is that one expects saturation of the urban network in 2005. The
expected increase of traffic for 2005 makes the average peak period speed drop from 38
to 23.7 km/h. The marginal external congestion costs of the heavy vehicles (bus, tram
and truck) equal twice the cost of passenger cars.