Traffic lights always on green

[traffic-light-man]

I assume using a single aspect GA without authorisation from the DfT is against the TSRGD.

I wasn't aware you needed authorisation to use filter arrows?

You don't, providing the signal face complies to the TSRGD.

A single aspect head doesn't comply, AFAIK.

[Keiji]

Oh - sorry, I misunderstood. I thought you meant (and was surprised that) you'd need authorisation for my preferred setup, which is a "single" filter aspect attached to the main red-amber-green for turning right in a J-shape. Whereas what you meant by single was having it all on its own.

[Gareth]

I don't see they need for permanent green arrows in most occassions. I really do think that a sensible road layout, markings and position of signals can make it clear to through traffic that the signals do not apply to them. I'm not even sure where the stop line is in the OP's example. It seems to form a part of the hatchings. This is also a situation where red & amber arrow aspects would be helpful.

I don't know of any local examples anymore but the old Paradise Street bus station in Liverpool City Centre had a left filter arrow permanently on,allowing buses to turn into the station.

Not quite the same thing, but there were also a set of tin lanterns (Edge Lane/St Oswalds Street) which had pedestrian signals on most arms but they were all dead. Despite the vehicle signals being on and behaving normally, the ped lanterns were always dark and the buttons didn't illuminate either. There was a pedestrian crossings on one of the exiting arms and so the vehicle lights were just always on green. They were replaced with mellors (like for like) in 1991 but had the exact same problem, suggesting the same controller was in use. It was eventually fixed a couple of years later.

[Bryn666]

There is a set in Brixham that has a permanent left arrow. Currently the lights are off due to roadworks... barring the left arrow.

[xfield]

I don't know if this is true now, but in Germany, if you stayed at a certain speed, you would never hit a red light.

The speed of light + 1 mph?

In all seriousness, isn't that a "greenwave" - how is it possible to guarantee that for everybody?

[Chris5156]

I don't know if this is true now, but in Germany, if you stayed at a certain speed, you would never hit a red light.

The speed of light + 1 mph?

In all seriousness, isn't that a "greenwave" - how is it possible to guarantee that for everybody?

You may well hit a red light the first time you approach a set of lights that forms part of the sequence. However, when it turns green, providing you maintain the correct speed, all the rest will be green too.

So it's not so much that everyone always gets green; more that once you get a green light you'll find the rest all follow.

[boing_uk]

Well not quite so. I wrote an article in the wiki on green progression explaining it a bit better.

[Keiji]

I don't know if this is true now, but in Germany, if you stayed at a certain speed, you would never hit a red light.

The speed of light + 1 mph?

In all seriousness, isn't that a "greenwave" - how is it possible to guarantee that for everybody?

You may well hit a red light the first time you approach a set of lights that forms part of the sequence. However, when it turns green, providing you maintain the correct speed, all the rest will be green too.

So it's not so much that everyone always gets green; more that once you get a green light you'll find the rest all follow.

Only if you follow the priority route though, surely?

[Glen]

I don't see they need for permanent green arrows in most occassions. I really do think that a sensible road layout, markings and position of signals can make it clear to through traffic that the signals do not apply to them.

It depends on what the existing road layout and space will allow.
The example the boing posted shows you can have a signal for right turn that is unlikely to misinterpreted by other traffic, but there is plenty of room to separate the right turn lane there and the width of the rest of the carriageway also makes it more obvious.
But in urban street it is likely that the controlled and uncontrolled lanes are going to have to be right next to each other so could potentially cause confusion to some drivers.

This is the example I mentioned in Inverness, without the green arrow it would be likely that some drivers would stop at the signals, even though there would be no signal to their nearside or stop line across their lane.
It would still be technically correct without the green arrow, but it reduces the potential of driver confusion.

[Ben302]

Permanent greens here and here

[A72]

Permanent greens here and here

Follow the second example's road for bit, and you get to here. Would these be candidates for the botched thread? There's something not quite right about them.

[Keiji]

Yes - text too small. I think they've already been posted, though...

[dragonv480]

And, conversely, always red (unless you have the electronic gizmo to activate them).

http://goo.gl/maps/BRbuF

No longer true; these have been replaced recently with new heads and poles (and controller?) and now although there is now a "no stunt bikes" sign with a "permit holders only" supplement, the lights do go green as you approach them, then return to rest on red.

[hughster]

permagreenon its own signal head

IMHO, red/amber arrow lights at this sort of junction would be much clearer and avoid messes like this.

Just for illustrative purposes...

Before:



After:

[WHBM]

I don't see they need for permanent green arrows in most occasions.

I do get the impression that many of them are retro-fits, to deal with experience of through traffic stopping unnecessarily.

Louvred signals, to be visible only to traffic in the turn lane, so often end up with poor/concealed visibility of the lights. I dislike them. Has anyone any experience here with the USA style, done not with louvres but with ground-glass optics on the lens itself, these give much more accuracy of light direction and focus, the whole set of aspects will come into view as you move into the turn lane, but show nothing when you are one lane to one side.

[jcpren]

I do get the impression that many of them are retro-fits, to deal with experience of through traffic stopping unnecessarily.

That's exactly what happened here. And as has been mentioned about other similar installations, the green arrow remains lit even when the rest of the set has failed.

(I wonder... Could you legally pass the stop line on red, and then use the roundabout to turn left?)

[Pilgrim Dan]

Set #1, with stop line, so presumably could be programmed to change

Set #2

[Johnathan404]

It dawned on me that this one counts recently while trying to cross the road.

M27 J9 is a fairly typical filter lane example. Compare with J7, which must be of a similar age.

[traffic-light-man]

Does a green arrow not impose a mandatory 'movement in direction of arrows only'? So a green right arrow display without a green straight arrow means you must turn right.

Just a thought.

NB: I know in reality the likelihood of your average driver seeing it this way is very, very unlikely.

[M4Mark]

Does a green arrow not impose a mandatory 'movement in direction of arrows only'? So a green right arrow display without a green straight arrow means you must turn right.

Only applies in relation to a movement crossing the stop line.

The straight on movement as Boing's example shows should ideally have no need for stop line or signals.
I only know of one "Permanent Green Arrow" in the authority I'm working for which has been there since the mid 1990s.

I suppose a RAG head that never changes is the only legal way to do it.

Possibly but a full signal head could give an incorrect impression that the light may change up to red causing people to speed up where as an individual green arrow is obviously different.

I assume using a single aspect GA without authorisation from the DfT is against the TSRGD.

You never ask questions to which you don't want to know the answer!