On Tue, 28 Jul 2009 14:27:58 +0100, Mike Bristow
wrote:
In article ,
Derek Geldard wrote:
It's probably done on purpose on grounds of cost: lights with a
fixed (or timed) pattern will be cheaper to buy and maintain than
lights with sensors etc.

That, as I understand that would be illegal.

I find that difficult to believe. I don't think the lights at the
junction of Bush Road and Leytonstone High Road have sensors, for
example. they certainly don't have the obvious ones that sit on
top of the lights (although they might have a loop in the road
itself, I suppose).


No traffic lights on a public road, whether temporary or permanent,
can be installed without sensors. Almost all permanent lights have
sensor loops in the road surface. Only a few have the sensors on top
of the traffic light that are universal in temporary installations.