London Traffic Lights?

[AutomaticBeloved]

Possibly a dumb question, but is there a reason why traffic lights in London don't have the white reflective border that other areas have?

[ChrisH]

Not a dumb question at all. A few reasons:

- (Historically) many more traffic signals in London than other places, so less need to highlight them with a backing board
- Omitting the backing board saves a few mm which can sometimes make a difference at tight junctions

Backing boards are often installed where deemed necessary, e.g. on east- or west-facing approaches where low sun could obscure the lights.

[jervi]

In Lincoln, another historic city, many of the traffic lights don't have the white reflective border.
Also a set of traffic lights were replaced in the centre of Sleaford (just down the A15 from Lincoln) a couple of months ago. They did have a white reflective board before, however now they don't. Which is a bit odd tbh.

[pendlewitch]

I have noticed this and it is not good. Nearly 10% of the population are red-green color blind, so this border is important to enable drivers to see the traffic light phase from a distance, especially at night.
Is anyone else old enough to remember when the amber light was in a white painted block? This was similarly useful to color blind drivers.

[nowster]

I noticed last week that the traffic lights in Salford (especially A6 The Crescent/Chapel St) don't have borders, either.

[Bryn666]

The borders have never been required on roads with a 30 limit (or less) so London was simply taking advantage of this fact. The amount of maintenance the borders require would have been insane money for no benefit either.

Until recently it was also rare that borders were reflective - the old Mellor borders were usually just painted.

Whilst the concern about red/green colour blindness is valid, remember approach speeds to sites without borders should be low enough that a driver can discern the position of the signal relative to the unit well within the stopping distance required.

Most of the world does not use borders at signals at all.

[Berk]

Australia/New Zealand/South Africa??

[WHBM]

This one has come up before, and the various justifications (London has a lot of signals; it's because of narrow roads; etc) are just as applicable in places elsewhere, so I've always just put it down to local decisions on standards. Different places have their own staff making different decisions. There's no compulsion one way or the other.

[trickstat]

I have noticed this and it is not good. Nearly 10% of the population are red-green color blind, so this border is important to enable drivers to see the traffic light phase from a distance, especially at night.
Is anyone else old enough to remember when the amber light was in a white painted block? This was similarly useful to color blind drivers.

Nearly 10% of the male population are red-green colour blind. Perhaps fewer than 1% of females have the same condition so overall it is about 5%. Maybe a little higher if you allow for a slightly higher percentage of males holding a licence.

[Chris5156]

This one has come up before, and the various justifications (London has a lot of signals; it's because of narrow roads; etc) are just as applicable in places elsewhere, so I've always just put it down to local decisions on standards. Different places have their own staff making different decisions. There's no compulsion one way or the other.

Agreed, I think it’s as least as much this reason as anything else.

What’s interesting is hearing that other places - Salford, Lincoln - are now installing signals without backing boards. The reason London’s practice used to feel so different is that, until a few years ago, it was virtually unique in sometimes installing signals without backing boards, and the practice was unheard-of in the rest of the country. For most parts of the country it still is.

[Dougman]

Or one for when you can't decide

[Chris Bertram]

Or one for when you can't decide

Mellor signals look awful without a border, or with a very tight border.

[Bryn666]

This one has come up before, and the various justifications (London has a lot of signals; it's because of narrow roads; etc) are just as applicable in places elsewhere, so I've always just put it down to local decisions on standards. Different places have their own staff making different decisions. There's no compulsion one way or the other.

Agreed, I think it’s as least as much this reason as anything else.

What’s interesting is hearing that other places - Salford, Lincoln - are now installing signals without backing boards. The reason London’s practice used to feel so different is that, until a few years ago, it was virtually unique in sometimes installing signals without backing boards, and the practice was unheard-of in the rest of the country. For most parts of the country it still is.

Likewise in Blackburn. The borders ultimately are a maintenance headache.

[Chris Bertram]

This one has come up before, and the various justifications (London has a lot of signals; it's because of narrow roads; etc) are just as applicable in places elsewhere, so I've always just put it down to local decisions on standards. Different places have their own staff making different decisions. There's no compulsion one way or the other.

Agreed, I think it’s as least as much this reason as anything else.

What’s interesting is hearing that other places - Salford, Lincoln - are now installing signals without backing boards. The reason London’s practice used to feel so different is that, until a few years ago, it was virtually unique in sometimes installing signals without backing boards, and the practice was unheard-of in the rest of the country. For most parts of the country it still is.

Likewise in Blackburn. The borders ultimately are a maintenance headache.

AFAICS Mellor borders are/were screwed onto the sides of the signal head, and were prone to dropping off. Borders on signals of other designs seem to surround the head completely. I guess this means they drop off less often.

[Gareth]

Yes, they were separate bits fixed onto the backing board. I recall seeing some Mellors in London where the border was fixed directly onto the head itself, the backing board being absent. Looked awful.

The Plessey Tin signals had yellow painted borders.

What’s interesting about London is that they never used backing boards on their Tin and SGE signals, however, it appears that when they first started using Mellors, they initially installed them like in the rest of the country - with grey poles and backing boards with white borders. Around the turn of the 80s, this switched to black poles and no backing boards.

[DB617]

Most of the Mellors in my area are missing at least one portion of the backing board. One of many really bad optics on my local roads, where things all appear to be falling apart from lack of love, with particularly bad neglect on the airport route, which is arguably the most strategic in the county.

[darkcape]

Most of Nottingham City Council's signals don't have backing boards.

[ElsieSeedlow]

The explanation I heard was that the TSCU (forerunner of TfL Traffic Control) didn't think Mellors were a great idea and decided not to fit them when changing out from stripey poles and individual lanterns to the new combined signal heads.
Now we don't use incandescent bulbs but shining LEDs the actual lanterns are bright enough to be seen in my opinion and a border is not needed.

[Gareth]

The thing is, from video and photographic evidence, it seems London did indeed fit Mellors with backing boards and standard grey poles initially. It seems it was around the turn of the 80s that they switched to no backing boards and black poles.

[ElsieSeedlow]

Yes I remember them too.
A possible reason for the Mellors is that they were on what were trunk roads and therefore funded by DoT or DoE, as was? There was a lot of de-trunking in the early 80s