Bus Priority Strategy: Justification and Environmental Aspects

Abstract

The benefits and costs of implementing a bus preemption system at isolated intersections and at intersections forming an open arterial network were investigated. Trade‐off analyses were performed on measures of road user costs. Several hypothetical combinations of automobile and bus flow rates were investigated to determine the traffic conditions for which preemption is justified. Travel time delay and fuel consumption were used as measures of effectiveness. The measures of effectiveness were estimated utilizing the Urban Traffic Control System/Bus Priority System (UTCS/BPS) and Network Flow Simulation for Urban Traffic Control System (NETSIM) traffic flow simulation computer programs. The study concluded that the economic justification of bus preemption for a network is dependent upon the network geometric configuration and network traffic flows rather than the individual intersection's economic viability. The analysis indicated that the benefits of bus preemption increased at the internal intersections of the network. A possible cause of this was found to be vehicle platooning. Bus preemption proved to cause higher vehicular emission rates than the non‐preemption case.