On Mon, 5 Sep 2016 20:13:21 +0100, Nightjar wrote:


Modern temporary traffic lights always use traffic sensors. However,
they also have a maximum length of red signal, which varies from 2-5
minutes, depending upon normal traffic flow on the road.

Contrary to urban legend, temporary traffic lights are compulsory lights
and passing the 'If Red Light Shows Wait Here' sign, or the lights if
there is no sign, when the red light is showing is an offence.

ISTR that at one time when they only exhibited a red and green that
wasn't the case then temporary traffic lights adopted the three lamp
Red Green Amber combinations so that they could be made compulsory.
The urban legend probably stems from the two lamp era, which leads to
wonder what if any offence may be commited if you ignore the geezer
with a Stop /Go board when he turns it to stop as you approach.

G.Harman