Split Cycle Offset Optimisation Technique (SCOOT) is an adaptive traffic control system for controlled road crossings developed by the Transport Research Laboratory. It is used extensively throughout the United Kingdom as well as in other countries.
SCOOT automatically adjusts the traffic signal delays to adapt to traffic conditions, using data from traffic sensors. Sensor data is gathered from multiple sensors within clusters of road crossings called "regions", and used to guide crossing timing decisions throughout each region. SCOOT has been demonstrated to yield improvements in traffic performance of the order of 20% compared to fixed timing systems.
Placebo buttons
According to a BBC News report, data from pedestrian signal buttons may or may not have any real effect on SCOOT-controlled crossing timings, depending on their location and the time of day, and some junctions may be completely automated, with push-buttons which do not have any effect at all, effectively acting as placebo buttons. However, the same report quotes a Transport for London source as stating that the majority of pedestrian junctions in London do respond to the pedestrian signal button.