Abstract
Road-user charges have been discussed extensively in economic literature. Surprisingly, little attention has been devoted to the most common example of these charges: a toll imposed on a single road where all competing roads are free. When the level of this sub-optimal charge is determined the benefits of reduced traffic load should be balanced against the damage of diverted traffic. The desirability of a single toll is examined with respect to congestion, the supply of the free road, and travel demand.