Bus priority : Route 220 monitoring.

Annual monitoring has taken place since 1992 on the effects on Route 220 (in West London) of a successful series of bus priority measures. The variable nature of traffic congestion makes difficult the assessment of how well bus lanes perform - "before and after" comparisons depend on chance circumstances. The paper discusses ways of assessing the effects of a bus lane despite this problem. Results of the monitoring studies are presented, including effects on journey time, effects on reliability, economic performance of the measures, effects on patronage of the service and information on the attitudes of passengers.