Traffic lights are sometimes centrally controlled by monitors or by computers to allow them to be coordinated in real time to deal with changing traffic patterns. Video cameras, or sensors buried in the pavement can be used to monitor traffic patterns across a city.

Who is responsible for traffic lights?

Except for temporary traffic restrictions related to road works, all traffic lights and signals are the responsibility of Transport for London. Requests for reinstating traffic lights which are out of service should be made to Transport for London on 0343 222 1234.

How are traffic lights controlled?

Traffic signal controllers are electronic devices located at intersections that control the sequence of the lights. ... Traffic flow information is picked up by the detectors from the roadway and transmitted to the computer system for processing. The detectors are normally embedded in or suspended above the roadway.