Those folks from the hill of pigs are at it again what with their innovative switching off their speed cameras, now this:-
As mentioned by Jeremy Vine, so what do people think of this method of encouraging keeping to the limit:-
bbc.co.uk/news/uk-england-wiltshire-13445550
I think it sounds great overall…
As long as the sensors are far enough back that you can’y fly on through on yellow it seems like a decent idea
Kin great idea considering there are no red light cameras either !! 
In Spain there are semaforos (one of the expat drivers will correct me on this), where there is a pair of flashing amber lights which will change to red if you speed across a measured distance. Jump the red light and you will get a ticket from the guardia if they’re around. These are not at junctions, mind you if you do stop at the red light the Spanish don’t half get ■■■■■■ off at you.
As well as the spanish, the belgians use groene golf. lights stay on green if you drive below the limit, dead handy past the crem