Unique Traffic Signals
Moderator: Site Management Team
Re: Unique Traffic Signals
Here is a bit of an odd situation the dead end side road had its own signals to get out at one point evident by the burned away stop line and empty NAL socket next to it. But they later removed the signals and turned it into a give way whilst the rest of the junction is under signal control. I can't think why they'd remove it given its only a small side road so I imagine it didn't cause that many issues. I'm not overly keen on the installation anyway i think it looks quite messy the placement of signal heads isn't great because it's a heavily used double decker bus route so it's easy for signals to be blocked off in busy traffic and missed completely.
Re: Unique Traffic Signals
Isn't it a bit embarrassing as a country when the deliberately erased stop-line is about as clear as the ones that are intended to be present.L.J.D wrote: ↑Tue Apr 12, 2022 20:39 Here is a bit of an odd situation the dead end side road had its own signals to get out at one point evident by the burned away stop line and empty NAL socket next to it. But they later removed the signals and turned it into a give way whilst the rest of the junction is under signal control. I can't think why they'd remove it given its only a small side road so I imagine it didn't cause that many issues. I'm not overly keen on the installation anyway i think it looks quite messy the placement of signal heads isn't great because it's a heavily used double decker bus route so it's easy for signals to be blocked off in busy traffic and missed completely.
-
- Member
- Posts: 215
- Joined: Thu Apr 28, 2011 19:45
Re: Unique Traffic Signals
If you go back through the Streetview history, I can't see any point when traffic lights were ever present on that road. The traffic lights only appeared between May 11 and October 12 but in the first Streetview image after installation, there is no traffic light on that road. So if there was ever a traffic light on that road, it was (very) short lived. I wonder if the socket was installed as future proofing, in case it was ever needed in the future?L.J.D wrote: ↑Tue Apr 12, 2022 20:39 Here is a bit of an odd situation the dead end side road had its own signals to get out at one point evident by the burned away stop line and empty NAL socket next to it. But they later removed the signals and turned it into a give way whilst the rest of the junction is under signal control. I can't think why they'd remove it given its only a small side road so I imagine it didn't cause that many issues. I'm not overly keen on the installation anyway i think it looks quite messy the placement of signal heads isn't great because it's a heavily used double decker bus route so it's easy for signals to be blocked off in busy traffic and missed completely.
Re: Unique Traffic Signals
There used to be one here before the junction was remodelled into a 5 way junction.traffic-light-man wrote: ↑Sat Apr 09, 2022 15:53 How many roundabout have filter arrows? Not quite unique because I'm about to list two, but I presume they're not very common at all.
Just a thought prompted by this one I came across on street view, though in this instance I can't quite work out why you wouldn't just give it a full RAGa instead.
This is another one, at a junction should really be a T-junction but instead is a piddly little roundabout that's signalised as if it was a T-junction. It does provide some useful u-turn opportunities, though.
Are there any others kicking around?
Re: Unique Traffic Signals
Not really as jnty said but it's one of them interesting places where in this case the middle lane can go left or straight, but the left turn has a filter. So someone waiting for the filter could be stuck behind someone going straight and would have to change lane or wait for the full greenBryn666 wrote: ↑Tue Apr 12, 2022 12:02That appears to invite you to turn directly into the path of vehicles already on the roundabout entering the M77. Yikes! Who signed THAT off?pjr10th wrote: ↑Tue Apr 12, 2022 00:49 What I imagine must be a very early Signalised roundabout with a filter arrow onto the motorway in Renfrewshire. Leggatston Dr
https://maps.app.goo.gl/P46robfMRjYzj4wa8. Also interestingly uses banned turned signs.
Re: Unique Traffic Signals
So this junction on the A4 confuses me, because the light is green for North and South bound traffic here. So my question is, should you treat it like a roundabout and give way to the right, or do they have to give way to you, treating it like a regular right turn?
Is there anything like this anywhere else?
Is there anything like this anywhere else?
Re: Unique Traffic Signals
Remember the green light doesn't mean go.Skipsy wrote: ↑Fri Apr 15, 2022 19:44 So this junction on the A4 confuses me, because the light is green for North and South bound traffic here. So my question is, should you treat it like a roundabout and give way to the right, or do they have to give way to you, treating it like a regular right turn?
Is there anything like this anywhere else?
The highway code wording is
you may go on if the way is clear.
Make poetry history.
Did you know there's more to SABRE than just the Forums?
Help with maps using the new online calibrator.
Add your roads knowledge to the SABRE Wiki.
Did you know there's more to SABRE than just the Forums?
Help with maps using the new online calibrator.
Add your roads knowledge to the SABRE Wiki.
Re: Unique Traffic Signals
It's bad design as it is unclear.Skipsy wrote: ↑Fri Apr 15, 2022 19:44 So this junction on the A4 confuses me, because the light is green for North and South bound traffic here. So my question is, should you treat it like a roundabout and give way to the right, or do they have to give way to you, treating it like a regular right turn?
Is there anything like this anywhere else?
However imo, you're turning right, so you've got to give way to oncoming vehicles. There's no give way line for joining traffic, so that rule doesn't apply.
There's a similar - yet slightly different - junction near me:
https://maps.app.goo.gl/q22fYTXAEaBpSNXJ6
Re: Unique Traffic Signals
That wasn't a pelican but this is. Looking at the PBUs it had a flashing amber stage despite the arrow. This setup is unique in a lot of other ways two. Got replaced with 2 puffin crossings eventually but still a unique setup
-
- Member
- Posts: 172
- Joined: Wed Jan 12, 2022 03:58
- Location: Krasnoyarsk, Russia
Re: Unique Traffic Signals
This is not in Britain (it's in South Africa) but this is really strange.
https://www.google.com/maps/@-25.757638 ... 312!8i6656
I don't understand why would a grade-separated interchange need traffic lights.
https://www.google.com/maps/@-25.757638 ... 312!8i6656
I don't understand why would a grade-separated interchange need traffic lights.
Re: Unique Traffic Signals
Ramp metering in busy periods so traffic can merge when there's a gap to stop congestion on the mainline. UK has plenty of examples as do alot of countries.WhiteBlueRed wrote: ↑Thu Apr 21, 2022 08:13 This is not in Britain (it's in South Africa) but this is really strange.
https://www.google.com/maps/@-25.757638 ... 312!8i6656
I don't understand why would a grade-separated interchange need traffic lights.
Re: Unique Traffic Signals
I think metering wouldn't usually have signals on the mainline though? This looks like a reaction to a short slip road causing problems at peak times. Similar signals can be found on the A90 on approach to Edinburgh.L.J.D wrote: ↑Thu Apr 21, 2022 10:17Ramp metering in busy periods so traffic can merge when there's a gap to stop congestion on the mainline. UK has plenty of examples as do alot of countries.WhiteBlueRed wrote: ↑Thu Apr 21, 2022 08:13 This is not in Britain (it's in South Africa) but this is really strange.
https://www.google.com/maps/@-25.757638 ... 312!8i6656
I don't understand why would a grade-separated interchange need traffic lights.
- Nathan_A_RF
- Member
- Posts: 726
- Joined: Sat Apr 05, 2014 12:53
- Location: East Sussex/Southampton
- Contact:
Re: Unique Traffic Signals
There's a plethora of signals on one of the slip roads at Redbridge here
https://www.google.co.uk/maps/@50.92174 ... 384!8i8192
https://www.google.co.uk/maps/@50.92174 ... 384!8i8192
Re: Unique Traffic Signals
It’s a very short merge in what must be an extremely busy location. It’s also an isolated GSJ on a road with signalised junctions either side. In this situation the grade separation removes right turns from the junction, which massively increases its capacity, even if it’s not possible for the merges to be free flowing.jnty wrote: ↑Thu Apr 21, 2022 13:43I think metering wouldn't usually have signals on the mainline though? This looks like a reaction to a short slip road causing problems at peak times. Similar signals can be found on the A90 on approach to Edinburgh.L.J.D wrote: ↑Thu Apr 21, 2022 10:17Ramp metering in busy periods so traffic can merge when there's a gap to stop congestion on the mainline. UK has plenty of examples as do alot of countries.WhiteBlueRed wrote: ↑Thu Apr 21, 2022 08:13 This is not in Britain (it's in South Africa) but this is really strange.
https://www.google.com/maps/@-25.757638 ... 312!8i6656
I don't understand why would a grade-separated interchange need traffic lights.
There’s something very similar at Poplar, the northern end of the Blackwall Tunnel, which is a six ramp parclo in which all the merges are signalised. That’s partly because the merges are ridiculously short but also to ration the time each flow of traffic gets - otherwise A12 to A102 would dominate and turning flows would struggle to reach the tunnel.
Chris
Roads.org.uk
Roads.org.uk
Re: Unique Traffic Signals
I know it's been mentioned on this forum before but this unique set up always deserves a mention.
Re: Unique Traffic Signals
This is a new example of ramp metering on a local road.
https://www.google.co.uk/maps/@53.78316 ... 384!8i8192
https://www.google.co.uk/maps/@53.78316 ... 384!8i8192
Re: Unique Traffic Signals
I think the definition of ramp metering would demand that the main line is unsignalled? I think this is just a signalised merge.tom66 wrote: ↑Sat Apr 23, 2022 09:22 This is a new example of ramp metering on a local road.
https://www.google.co.uk/maps/@53.78316 ... 384!8i8192
- traffic-light-man
- Member
- Posts: 4735
- Joined: Fri Sep 01, 2006 18:45
- Location: Liverpool, UK
Re: Unique Traffic Signals
As jnty said further upthread, it's not a ramp meter if it's directly controlling the conflicts at the merge. It's just a junction.
Simon
Re: Unique Traffic Signals
If the South African example counts as ramp metering then this does too!
Yes, it's just a signalised merge, although the visibility is rather good so I think it was primarily included to improve flow rather than safety.
Yes, it's just a signalised merge, although the visibility is rather good so I think it was primarily included to improve flow rather than safety.
- traffic-light-man
- Member
- Posts: 4735
- Joined: Fri Sep 01, 2006 18:45
- Location: Liverpool, UK
Re: Unique Traffic Signals
Yes, and so the South African example isn't a ramp meter either. It even has pedestrian facilities on the slip road approach.
Simon