Red to Green in the UK?

[traffic-light-man]

Hi All,

Whilst snooping through old footage again, I came across ]this Pathe video.



It seems to show a tin signal going from red straight to green at around 2:17. I thought initially that the amber lamp may have been burned out, however at just after 2:05, we see the signal run to red through amber.

Was red straight to green allowed at one point in the UK?

[Bryn666]

There were some experiments I think once upon a time?

[WHBM]

Temporary Traffic Signals until about 1970 only had two aspects, and went red to green and v. v. directly (just like Stop/Go boards !)

[Chris Bertram]

There were some experiments I think once upon a time?

Signals in Jersey omit red+amber as well.

[Chris Bertram]

Temporary Traffic Signals until about 1970 only had two aspects, and went red to green and v. v. directly (just like Stop/Go boards !)

1970 at the very very latest, I'd have said about 1966/7 more realistically.

[michael769]

There were some experiments I think once upon a time?

I have a very vague recollection that Red->Green was the norm originally with Red+Amber being introduced after a little while.

I've no idea where I've got this from so it's always possible by brain made it up!

[jedikiah]

There were some experiments I think once upon a time?

The experiments on removal of a starting amber were carried out in 1959 in Leicester.

[A303Paul]

Is it possible the thing was malfunctioning. It flicks from green to amber and back rapidly a few seconds before the main sequence.

Alternatively is the film maker trolling by messing about with the film sequence or interspersing a Dublin traffic light into it?

Also note the GO on the green aspect.

[Chris5156]

There were some experiments I think once upon a time?

The experiments on removal of a starting amber were carried out in 1959 in Leicester.

I've also seen an account of a trial to remove amber lights in the 1930s in London - at which time starting amber was already sufficiently established that this was considered quite a departure. It was found to be very unsuccessful very quickly.

[Pinzgauer]

Pathe got the title a bit wrong. It should read Traffic and Shops in Glasgow and London ! The early shots clearly show Glasgow Standard and Cunarder (maybe a Coronation) trams. The Fischer bow collectors are a bit of a giveaway. It then moves seamlessly to London Transportville.

Dumping my pendant's pen in the bucket - when did we cease using green lenses with "GO" on them? I remember "STOP" back painted on the red as a child, but amber and green were plain.

[jedikiah]

There were some experiments I think once upon a time?

The experiments on removal of a starting amber were carried out in 1959 in Leicester.

I've also seen an account of a trial to remove amber lights in the 1930s in London - at which time starting amber was already sufficiently established that this was considered quite a departure. It was found to be very unsuccessful very quickly.

My dad remembers the Leicester tests; it didn't cause confusion with the locals as it had been extensively advertised through the local newspapers in a era when these were still widely read (and there were still 2 separate ones). Not sure how visitors may have found them for the first time.

[paully]

Here's a set of lights with no amber in use on a public road:
https://goo.gl/maps/oTPZ8ikhfSz
It's a rising bollard that was put in about 10 years ago, I'm not convinced it's compliant. I've seem plenty of these on private roads but this is very much a council adopted road, as confirmed by the PDF on this page: http://www.pkc.gov.uk/article/4383/List-of-public-roads

[A303Paul]

This one in Manchester had the same sort of non amber traffic lights I think.

https://www.youtube.com/watch?v=i_Cw0QJU8ro

I wonder if any driver having been impaled on such a bollard has tried a case based on there being no amber light?

[ianwallis]

I wonder if any driver having been impaled on such a bollard has tried a case based on there being no amber light?

I can't speak with real authority on this but when we first installed rising bollards in Nottingham (late 80s early 90s) I'm sure the signals were just red and green. That being the case I would have assumed that this was the approved setup. Thinking about it, what would an amber signal mean in such a circumstance anyway. If you're letting only one vehicle through at a time then the second vehicle must stop - the amber signal would be too ambiguous to be used there surely.

ADDITIONAL - TR2207 Specification for rising bollards control system states "3.5 Separate red and green indicators shall, where provided, be provided to indicate to vehicle drivers the status of the bollards i.e. fully retracted, about to rise or fully raised."

I suspect that covers the lack of an amber signal.

[WhiteBlueRed]

I found a research paper about the effects of having a red+amber period versus not having one. It covers the Leicester experiment.
https://studylib.net/doc/18129045/revie ... at-traffic
By the way, I remember seeing a video of the Leicester experiment on YouTube, but I can't find it anymore. I think it was uploaded by British Pathe.

[tom66]

With the proliferation of automatic and electric vehicles a starting amber will make much less sense. I can have my car moving within the time it takes to react to the green signal (it is an EV, instant torque combined with brake hold.) It made a lot more sense when you had much heavier and more difficult to use clutches, compared with a less relaxed biting point and engine control, and a handbrake to modulate too. My dad's old Peugeot diesel was a bugger, given I had learned on a small petrol car. So I wonder if that could be a good reason to change the sequencing, at least for new installs.

From a traffic control perspective, is the red+amber phase treated as a 'true red' (as in the other phase can be showing amber while it is lit) or is it part of the intergreen phasing (it can only be shown when the opposing signal is on red?) If it can be shown while the other phase is amber, it adds to the efficiency argument, but if it is just preventing early movement in what would otherwise be a green phase, then it surely reduces the capacity of the junction somewhat.

[Chris584]

When I lived at Bounds Green in north London in the 1970s the cross roads outside the tube station were signalled with a separate right turn lane in both directions on Bounds Green Road. The lights, SGE if you’re interested, had straight and left turn arrows set of lights on the near side. On an island was a set with the same as the near side but also with a set alongside that showed a right turn arrow.
When the side roads lights had turned red, the lights for straight and left went from red to green without the starting amber but then returned to red in the normal way. The right turn lights then went to green arrow via a starting amber.
I believe the the red to green on the main drag was designed to stop right turning drivers mistaking it for their right turn light, almost acting like an ahead and left filter. If I can find a picture I’ll post it.

[WhiteBlueRed]

From a traffic control perspective, is the red+amber phase treated as a 'true red' (as in the other phase can be showing amber while it is lit) or is it part of the intergreen phasing (it can only be shown when the opposing signal is on red?) If it can be shown while the other phase is amber, it adds to the efficiency argument, but if it is just preventing early movement in what would otherwise be a green phase, then it surely reduces the capacity of the junction somewhat.

It is displayed at the last 2 seconds of the intergreen. The other signal does not necessarily have to be red, but can be amber.
For instance, if the intergreen is 3 seconds long, red+amber will be displayed at the last 2 seconds of the amber light. If the intergreen is 4 seconds long, red+amber will be displayed at the last second of the amber light.

[traffic-light-man]

The ambers are both part of the intergreen calculation, so in most cases you wouldn't gain any green time from the removal of the SA as it would need to be replaced with additional red time, you'd just often end up with more lost time when the green does eventually appear. It's more about drivers reacting to the change of the signals than the performance of the vehicle.

Though of course plenty of other places seem to get on fine without it...

[Vierwielen]

I grew up in South Africa. In the late 1950's I recall having a book (printed in the UK) that had a rotating disk which allowed the reader to view the colour sequence of British traffic lights. I recall noticing almost immediately that the British and South African sequences were different - the difference being the amber after the red.