Talk:Traffic-light signalling and operation

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Yukon reference[edit]

Regarding the sentence

"Yukon Territory signals, currently found only in Whitehorse, are mounted horizontally over the road, and additional signals facing the same direction are sometimes also mounted vertically on the vertical post that supports signal mounts."

Unless I am reading the sentence wrong, traffic lights mounted horizontally over the road as well as vertically on the support post at the same intersection can be found everywhere, not just the Yukon territory! In fact, some of the vertical lights are actually mounted on top of the vertical post to be seen at a distance, especially if the intersection is at the bottom of a hill. --Goldrushcavi 19:10, 10 June 2006 (UTC)

  • Yesterday I moved the section formerly titled "Traffic light mounting in Alberta and Yukon" under "Unusual traffic light designs," including the photo example, to the "Mounting" section in "Traffic light," combining it with what was already there. Mapsax 22:31, 3 October 2006 (UTC)


This article not only needs more sections, but the mass of information that I have classes as "examples" needs organised in some fashion. It's currently just spewed onto the page.

zoney talk 21:10, 22 June 2006 (UTC)

Needs some photos[edit]

I think this page is informative, but the provision of photos of the unusual traffic lights alongside the text would be even better. LR4087 05:35, 28 August 2006 (UTC)

Suggestion of content I can't verify[edit]

The City of New York may still have some older two-color (red/green only, no yellow) traffic signals in service. I remember seeing this on the web site however my company firewall won't seem to let me in there to verify if this is still true. Perhaps someone else can check it out and update this article accordingly? Fjbfour 12:16, 8 December 2006 (UTC)

Flashing green[edit]

In parts of Canada (the Maritime Provinces, Quebec, Ontario and Alberta), a flashing green light has a special meaning. It is only shown in one direction, with the other three directions in a 4-way intersection having a red light. So, then, what does it mean in British Columbia? Quick Google searches indicate it means there is an unoccupied pedestrian crossing. Confirm/deny? Source and add please. SchmuckyTheCat 17:04, 8 January 2007 (UTC)

Considering I lived in British Columbia for 22-years, I can confirm that this is wholly correct. Do I have a source? No. :: Colin Keigher (Talk) 18:17, 8 January 2007 (UTC)

Original Research[edit]

This whole article probably needs to be scrapped or merged into "Traffic lights", but I put OR on it for starters for the following reasons:

1. There is no objective way to decide what an "unusual" use of a traffic light is

2. If something is an unusual use, it might very well not be labeled as such in the source, meaning that it still can't be objectively included

3. There are lots of statements (see "Flashing yellow arrow" for example) that indicate that statistics were interpreted or other primary sources were used to generate new information... hence, original research -- 06:49, 24 October 2007 (UTC)


Taken out and copied here:

"Similarly, in West Germany, there were at one time changing white lights before the colored traffic lights on surface highways, displaying the speed that one must drive from that place to catch a green light and avoid stopping. These may still exist there."

I think there were on a few larger streets and highways, but this is not enough for mentioning. We need more verification on this. Unfortunately, I cannot remember the right name for that system. I haven't seen such electronic signs for some decades anymore. I assume the reason for that was to save gas, because exhausts are less if the car is on the move rather than waiting at a traffic light (where most motorists do not shut off their engines). -- Scriberius (talk) 09:34, 6 January 2008 (UTC) from Germany

This was called a "signal speed funnel." It was created in Germany in the 1960s for use on highways, so the motorist traveling at the indicated speed would find the signal green. They gave up on it, because nobody slowed down to get the green light. Popular Science had an article on it in the 1960s. — Preceding unsigned comment added by (talk) 23:15, 29 August 2011 (UTC)

Left turn signals, Dallas phasing, flashing yellow arrows, new MUTCD--Unusual???[edit]

I was looking through the proposed Amendments for the New 2009 MUTCD, found here, and (using the "clean text" version) starting on Page 289 it looks like there will be FOUR different displays allowed in the USA for permissive left and right turns (and this is my source for the following):

  • The "normal" protected/permissive signal that allows the permissive left turn on the green light that is displayed for the adjacent through traffic.
  • The so-called "Dallas display" that can display a green ball for a permissive movement when the main light is red. (Note that the FHWA's New MUTCD prohibits this display for new signals.)
  • The flashing yellow arrow display that is listed in the article as being installed in Oregon, Michigan, and elsewhere. This will be required in the MUTCD to be either a four-section display or a three-section display with a bi-modal arrow; flashing yellow and steady yellow will be required to be displayed from different signal sections. Also note that the flashing yellow arrow will need to be followed by either a steady green arrow or a steady yellow arrow.
  • The flashing red arrow, BUT this is allowed to be used only in special situations requiring a full stop before turning left during the permissive left turn interval. Will operate similar to Michigan's flashing red ball, but using a flashing red arrow instead of a flashing red ball. Also note that the flashing red arrow will need to be followed by either a steady green arrow or a steady yellow arrow; change directly from flashing red to steady red will not be allowed.

For the change from flashing red or yellow arrow to steady yellow arrow, the steady yellow arrow comes on at the same time as the oncoming traffic yellow light, eliminating the yellow trap. Of the four allowed signal displays, only the first kind listed above is susceptible to the yellow trap (assuming they are correctly installed).

Given that all four of these kinds of signals are in the MUTCD, I don't know if any of them can be considered "unusual" in the United States. Then again, if we want to have a worldwide view of the subject of unusual uses of traffic lights, these are signal displays that may or may not be used in places outside the United States, and may be worth including. --Sleckronmich (talk) 04:33, 12 January 2008 (UTC)

Belisha beacons not mentioned[edit]

Its a light that regulated traffic, so its a traffic-light. (talk) 01:35, 8 March 2009 (UTC)


Many sections in the article only discuss United States, sometimes Canada and Australia. Much detail is given to different states of the US or provinces of Canada, but none (or next to none) attention given to Europe or other parts of the world. In particular, this happens a lot in "Unusual traffic light phases" and "Warnings of traffic light ahead". --Akral (talk) 09:31, 20 May 2012 (UTC)

amber vs yellow: i switched all to yellow[edit]

sorry! (mea culpa) I meant to put a comment on my change but brain hit Save. But, I counted the article and it had many more yellows than ambers, and I checked the MUTCD and it had yellow, and I googled .ca and .uk and .eu for "traffic signal light" and yellow vs amber, and yellow was always clearly more prevalent. So I made this article all yellow. (talk) 13:44, 2 July 2012 (UTC)

Never heard anyone refer to it as 'yellow'. I suppose it is still quite obvious but it makes the article seem rather childish.--ЗAНИA talk WB talk] 22:46, 4 March 2013 (UTC)

It was my understanding that the difference between yellow and amber glass related to the particular chemistry of the glass used. In traffic lights, the colour is "amber" from a glass-making perspective. Unfortunately I can not find a source for this. — Preceding unsigned comment added by (talk) 16:24, 18 April 2013 (UTC)


There has been an edit skirmish (not a quite an edit war yet) between editors Epicgenius and Kwamikagami. They have moved this article from "Traffic-light..." to "Traffic light..." and back twice.

I don't see anything in Hyphen that supports the hyphenated version. In my two decades as a traffic engineer, I've never seen it hyphenated. Still, it could be WP:ENGVAR thing, so I figured the polite thing is to discuss it before it gets too silly.

So, dear editors, please explain why you think it should be hyphenated or not.--Triskele Jim 17:00, 11 June 2013 (UTC)

Flashing yellow arrow confusion?[edit]

The following sentence is in the Flashing yellow arrow section of this article, but it sounds completely wrong to me. I'm not a traffic engineer, but maybe one is paying attention and can either fix the problem or set me straight.

To the driver turning left, the flashing yellow arrow means exactly the same as the steady green arrow.

A steady green arrow indicates that the oncoming traffic is stopped, and the left turn is protected. A flashing yellow arrow means that the oncoming traffic is, well, oncoming, and the left turn is allowed, but not protected. Pretty big difference.

Perhaps the last word should be "ball," not arrow, and the sentence could say "... exactly the same as the steady green ball." Stevekass (talk) 22:43, 4 October 2013 (UTC)

I am a traffic engineer and work for the Oregon Department of Transportation. There are multiple problems with the Flashing Yellow Arrow(FYA) section. First there is only mention of four types of FYA which excludes the original FYA developed by Jackson County Oregon which is a single lamp has a dual indication yellow/flashing yellow function. It doesn't discuss Red Transition, Red Extension, Gap dependent FYA, detector switching, how the phase pairs work together and the origin of FYA. All of these topics are fundamental to understanding how FYA works. — Preceding unsigned comment added by Fitzgerw (talkcontribs) 13:13, 20 August 2014 (UTC)

External links modified[edit]

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Question? Archived sources still need to be checked

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