How a fast lane may replace a congestion toll

This paper considers a congested bottleneck. A fast lane reserves a more than proportional share of capacity to a designated group of travelers. Travelers are otherwise identical and other travelers can use the reserved capacity when it would otherwise be idle. The paper shows that such a fast lane is always Pareto improving under Nash equilibrium in arrival times at the bottleneck and inelastic demand. It can replicate the arrival schedule and queueing outcomes of a toll that optimally charges a constant toll during part of the demand peak. Within some bounds, the fast lane scheme is still welfare improving when demand is elastic.

► Bottleneck congestion with general scheduling preferences.
► A fast lane scheme is defined.
► It can be robustly implemented in real time, requiring little information.
► It can always be made welfare improving.
► It is always Pareto improving when demand is perfectly inelastic.