Selective vehicle detection was the name of a
bus priority
Bus priority or transit signal priority (TSP) is a name for various techniques to improve service and reduce delay for mass transit vehicles at intersections (or junctions) controlled by traffic signals. TSP techniques are most commonly associa ...
system used by
London Buses
London Buses is the subsidiary of Transport for London (TfL) that manages most bus services in London, England. It was formed following the Greater London Authority Act 1999 that transferred control of London Regional Transport (LRT) bus s ...
to allow traffic signals to selectively favour buses' movement through intersection by changing traffic light sequences and timings as buses approach.
Following a successful large-scale trial in 1987, London Transport began introducing selective vehicle detection to shorten red lights or extend green lights in the 1990s.
[ ] This delivered journey time savings, as well as increased service reliability and reduced costs, as a smaller number of vehicles were required to deliver the same frequency.
For example, it was estimated that
route 15 could have a journey time 4 minutes shorter, due to the number of selective vehicle detection points passed.
The system worked using 'bus detectors' either mounted on lampposts by the side of the road or ground loops, which detect transmission made by transmitters aboard buses.
[ ]
Selective vehicle detection was replaced by the
iBus
The principal factors that characterize beer are bitterness, the variety of flavours present in the beverage and their intensity, ethanol, alcohol content, and colour. Standards for those characteristics allow a more objective and uniform determ ...
system in the late 2000s which tracks all London's buses, allowing passengers to be provided with audio-visual announcements and improved information on bus arrivals, as well as triggering bus priority at traffic lights.
iBus uses the
Global Positioning System
The Global Positioning System (GPS) is a satellite-based hyperbolic navigation system owned by the United States Space Force and operated by Mission Delta 31. It is one of the global navigation satellite systems (GNSS) that provide ge ...
instead of physical roadside equipment.
All buses in London were fitted with the iBus system by 2009.
See also
*
London iBus system
*
Bus priority and bus lanes in London
References
External links
Bus priority at traffic signals keeps London's buses movingSiemens Selective Vehicle DetectionAttitudes to bus priority schemesReview of bus priority at traffic signals around the worldAttitudes to bus priority schemes – Research Summary
Traffic signals
Road transport in London
Bus transport in London
Road traffic management
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