On Sun, 23 Nov 2008 05:09:43 -0800 (PST), Mr Thant
wrote:

[bus priority at traffic lights]

The system is called "extended green" and keeps the lights from
changing in the face of an approaching bus. There's no visible
indication a set of lights has it.

Not at the lights, no, but the old system uses beacons attached to
nearby lamp-posts on the approach. They look like the beacons used
for Countdown Mk 1 but apparently usually have a power supply whereas
the vehicle location beacons are usually battery-powered.

They don't know whether a bus is late or not, of course. The
replacement system, part of iBus, can fix this - but although it was a
requirement to be able to consider lateness I don't know whether it
will work like this initially.

Richard.