How many people have sat at 3am in the morning at a red light, whilst the lights let a non-existent car exit from a narrow side road? Not only is this annoying, it causes added pollution when the car sets off again and additional noise if the waiting car is outside your house.
Obviously there would need to be some lights that remain on as normal, but the vast majority could easily be switched to flashing amber. Most lights are largely totally unnecessary anyway except for perhaps a few hours in every day. Of course the people at the obsessed road safety pressure groups, like BRAKE, will no doubt claim that we will all get killed on day one, but the fact is that we won't and this system works perfectly well everywhere else in Europe.
I don't say that this measure is particularly important, it is simply something to make life easier for the poor old battered British motorist.