On 23 Nov, 14:33, Peter Heather wrote:
London buses were for donkeys' years fitted with transponders that the
signal loops pick up and could give priority to an approaching bus by
extending the green phase or cutting short the red period. Didn't help
much when there was another similarly equipped bus approaching on the
other arm of the junction though, nor was it capable of distinguishing
between a bus running late and one running early, so a bit crude. The
system was getting long in the tooth and other cleverer systems were
in development by the early 2000's.

No, it still seems to be the current preffered method, although I'm
guessing the technology's changed:
http://www.tfl.gov.uk/assets/downloa...s-priority.pdf

U