In message , at 23:30:56 on Sun, 6 Nov
2011, D A Stocks remarked:

The one I'm thinking of has a small traffic island, but you could
turn left past it; in other words you are saying the silver hatchback
here could immediately turn left (despite being in the wrong lane and
facing a red light): http://tinyurl.com/6kkff8b

It's facing a red light with a green arrow (well, if it wasn't
forward of the line it would be). So I think it's legal.

If you back up on the street view it's clear that the intention is to
have one lane each for left turn, straight on and right turn.

I'm aware of that (it's a junction I use at least once a week).

However, we got here by considering the legality of turning from
different lanes, and in particular whether the traffic lights are in any
sense linked to the lanes, or whether they just say which way you can
turn at that instant, from any of the lanes.

On the continent they do things better because the red (and possibly
amber) lights are arrows as well, so it's very clear which light is
controlling each traffic flow.

At the junction above it's clear which light is intended to control each
lane, but the question is whether that's merely advisory (as long as the
direction you want to go has a green). Similarly, the white arrows may
be only advisory.

My favourite example of this stupidity is this junction:

http://g.co/maps/ecedu

There is a large sign saying RIGHT TURNS GO FIRST, but you still see
people in lanes 1 and 2 taking off when the light for lane 3 changes.

And unlike the junction discussed above, the lanes there have "Ahead
Only" and "Turn Right" painted on the road, not just an arrow.
--
Roland Perry