HOW CONGESTION PRICING CAN INCREASE TRAFFIC VOLUMES

A combination of two dynamic models is presented to explore optimal congestion pricing in a multi-destination network. Vickrey’s bottleneck model (1969) deals with traffic demand while traffic operations are described by the LWR traffic flow model (Lighthill and Whitham, 1955 and Richards, 1956). The proposed combined LWR bottleneck model determines both user equilibrium and system optimum network conditions. It provides some surprising insights in the mechanisms of congestion. Congestion may be avoided by imposing an optimal dynamic toll. This has a significant positive impact on the performance of a network. A paradox appears where an optimal toll even lowers total trip costs and increases the traffic volume, without introducing congestion. Analysis with the combined LWR bottleneck model shows that congestion pricing can be even more beneficial than accepted until now.