Title

Improving Bus Travel Times with Passive Traffic Signal Coordination

Document Type

Journal Article

Publication Date

2009

Subject Area

operations - coordination, operations - traffic, infrastructure - bus/tram priority, infrastructure - bus/tram priority, infrastructure - traffic signals, ridership - commuting, place - urban, mode - bus

Keywords

Urban areas, Travel time, Traffic signal networks, Traffic signal coordination, Traffic signal control systems, Traffic delay, Synchronization (Traffic signals), Simulation, Signalized intersections, Signalised intersections, Perturbations, Optimization, Optimisation, Offsets (Traffic signal timing), Linked signals, Journey time, Intracity bus transportation, Interconnection (Traffic signals), Evolutionary algorithms, Computer simulation, Computer controlled signals, Bus transit, Bus priority, Automatic traffic signal control, Algorithms

Abstract

A simulation optimization model is outlined: traffic signal offsets in intersections are calculated to minimize the travel time of bus users in an urban network. The model considers a passive signal priority system and restricts the maximal incremental delay caused to car users. The simulation tool is able to trace discrete trajectories of both buses and cars in a network. It also evaluates potential perturbations that may cause time variations for average performance. Moreover, the optimization tool is based on evolutionary algorithms. The results of applying the traffic signal coordination model to a set of small trial networks are given. It is proved that the algorithm is able to design a sequence of signal offsets that reduces bus travel times by an 8.5% rate in a real network while maintaining the incremental car delay below 5%.