Can anyone explain to me, in layman's terms (I am only a bus driver,
after all) how the road sensors for traffic lights work?

Brian.

"Brian Robertson" wrote

Metal and metal detectors.

On Sun, 31 Aug 2008 02:35:37 +0100, Brian Robertson wrote
(in article ):

Hall effect and/or transponders. Google either/both for in depth explanations
better than I can give.

** Posted from http://www.teranews.com **

In uk.transport, Brian Robertson wrote:

... it soon will be.

"Brian Robertson" wrote in message
news:Jzmuk.95780$W71.79899@newsfe12.ams2...

some sort of radar/ doppler effect / hall effect thing on top of the lights
AFAIK. The ones on the bridge near here work really well. Sometimes as I'm
approaching 300yds or so away I can see them turn to red, but they change to
green again almost immediately if there's nothing coming. It can't be a
sensor in the road, as I never get near where I presume one would be before
they start to change again.

Mike P