OT Daft Idea or what?

[Handsome Jack]

But they often don't.

Sometimes it does give them that priority, but there is no way for them to know this unless they've been there before.

[Roger Hayter]

Unfortunately you are right. In which case, at a strange traffic light system, one should pause and only proceed right if one is sure one can see far enough down potentially colliding routes. If the locals get annoyed that's just one of those things. This is bad design.

[fred]

A green traffic light means proceed with caution.

There are two intersections where the green filter arrow comes on it does not indicate right of way. Regular accident spot.

[dennis]

Some prat drove into the side of a car I was driving when the filter arrow came on, totally oblivious to the fact the lights are still on green from the opposite direction.

It appears there are a lot of drivers that don't know what traffic lights indicate.

[Roger Hayter]

Obviously his fault in those circumstances, and he certainly should look where he is going; but I do think you can reasonably expect traffic lights not to do this deliberately.

[dennis]

Why? A filter arrow doesn't mean you have priority or that other lights are on red.

[Johnny B Good]

Quite frankly if that were true, then what is the point of a filter arrow?

It's certainly true that in some situations where an otherwise normal crossroad junction has a 3 way sequence applied, known only to regular users, that a situation arises where for those unfamiliar with the 3 way sequence are left to flounder about whether or not they can safely make a right turn since the traffic light lacks the right turn filter arrow normally installed to avoid such guessing games.

As per the usual caveat with traffic lights, the green means it's your turn but you're still obliged to avoid turning someone else's mistake into an accident, i.e. "Proceed with Caution!".

[Dave Plowman (News)]

The one exception is some left turn filters. Which may be active while the lights are green on the road you're joining. But pretty rare these days. They usually include give way markings on the road.

[bert]

So in such circumstances what is the point of it?

[Johnny B Good]

Not *usually*, the give way markings are *mandatory* in these cases. Also, those left turn filters are far from rare. The may be uncommon but they're commonplace enough as to not be classed as 'rarities'.

[Dave Plowman (News)]

Could be. But several round here have been re-phased so only operate when the lights of the road you're joining are red. Probably to slow down traffic flow like so many of these 'improvements'.