In article ,
misterroy wrote:
On Monday, September 5, 2016 at 8:36:44 PM UTC+1, charles wrote:
In article ,
misterroy wrote:
On my way to work a bridge is being repaired. Today I was in the
stream of traffic heading towards town, no cars going the other way.
Mid stream the lights went red, just as I reached them. I went
through. I reckon I travelled 100m between the lights and then about
600m up the hill before the lights changed. I realise there has to be
a margin to be sure a car gets through, but how big should the margin
be? Why when the lights have sensors do they never seem to be
switched on? It just looks like a crude timer is used. Under what
circumstances are the sensors on the lights used?

For at least the last 30 years, the use of sensors has been mandatory.

-- from KT24 in Surrey, England
I think the traffic lights here are just set on a timer and the sensors
not used, and the timer is always way way longer than is needed to clear
the lights. So if I am approaching a set of these lights at red, and I am
the only car on the road, how long should it take for them to show me a
green?

Temporary lights have switch for setting the distance between the two
ends. Perhasp this has been wrongly set because those who set them up don't
know the real distance and have set it to maximum.

--
from KT24 in Surrey, England