Talk:Traffic light/Archive 3

Horse signals
There are equine equivalents of signals for pedestrians and cyclists. They are higher up so horse-riders can reach them and usually have their own little light with a horse and rider. I'll take a picture of one and upload it if no-one objects. Prolinol (talk) 18:54, 8 November 2009 (UTC)

Better Writing
There are numerous problems with this article. More research, citations and better grammar are in order. Gingermint (talk) 20:47, 25 October 2009 (UTC)
 * It's one of those articles which has the fatal combination of lots of people knowing about the subject, but the ins and outs of the subject are massively different in various countries. But no-one knows enough about the subject as a whole to tie it all together. So we end up with stuff like: 'In Serbia and USA this happens but in the Ivory Coast and Belize this happens...' etc. etc. Prolinol (talk) 18:48, 8 November 2009 (UTC)

traffic signal v. stop light terminology
most people commonly interchange the terms "traffic signal" and "stop light" as if they mean the same thing. Now at first glance this appears correctly, but with a more through analasis and reasurch you can find infact that they are two completly different things. Now when people say "stop light" they mean, for the most part, the signal with red, yellow and green aka the "traffic signal". What they don't realize is that the actual definition of a "stop light" is a red flashing light in conjunction with a stop sign.(usually used when a stop may appear hidden or sudden.) Another problem with this is that dictionaries,encyclopedias and other seach databases also appear unaware of this difference making this more oblivious to people.
 * Language evolves. If 'stop light' makes people think 'that thing with red, amber and green' then that's what a stop light is. Simple. Prolinol (talk) 18:51, 8 November 2009 (UTC)


 * Oxford Dictionary of English:"stop light noun 1 a red traffic signal. N. Amer. a set of traffic lights. 2 (also Brit. stop lamp) another term forbrake light."

Light timing length
The sum of the amber and all-red time is 'intergreen time'. Are there any objections renaming the section accordingly? And it should be shifted somewhere else, as an operational concept as opposed to a legal one is discussed.Schwede66 (talk) 12:52, 4 October 2009 (UTC)

British Columbia red light movements
Is it worth noting that British Columbia has the unusual distinction of allowing a wide variety of movements when the light is red? Motorists may turn right, turn left on to a one way street (even from a two way), and may proceed on a red light at places where there is no intersection (mid block pedestrian only traffic lights) all after stopping at the red light. 174.6.228.216 (talk) 02:38, 3 November 2009 (UTC)


 * So that it's easier for others to appreciate your contribution, I point out here that British Columbia drives on the right side of the road. The turn on red rules might fit into the Turning signals and rules section. However, that section (if not the whole article) could do with some serious restructuring. The particular section might lend itself to its own article.
 * The article Pedestrian crossing has links to all the types of crossings that are around. I know that one of the British signalised crossings allows traffic to proceed with care when the light is still red, but pedestrians have already cleared the crossing. This is not documented on the relevant page, though. If and when those road rules get added to the particular crossing type, then the British Columbia mid block pedestrian crossing rule would best be added to that particular article. Schwede66 (talk) 04:56, 3 November 2009 (UTC)
 * I'll see if I can't draw up a draft using the existing text and drawing on some other rules from around the world. I don't want it to turn into a trivia section by merely adding facts. Flashing green lights seem to be able to go under both articles. I think they should fit in with the traffic light article and just have a small blurb in the pedestrian crossing article. Again, I don't want to add just the B.C. facts because that feels like it would come across as trivia. 174.6.228.216 (talk) 16:17, 4 November 2009 (UTC)

Garrett Morgan
Why isn't he mentioned as one of the great pioneers of the traffic light? —Preceding unsigned comment added by 70.161.130.102 (talk) 21:55, 9 February 2010 (UTC)

Because you neglected to pit it in 174.112.230.127 (talk) 21:50, 15 February 2010 (UTC)

Pittsburgh lefts in Eastern Massachusetts
Pittsburgh lefts may be seen on occasion in eastern Massachusetts. However, according to the current Massachusetts Driver's Manual, "When making any left turn you must first yield the right of way to any... [several bullet items effectively meaning 'anybody']" (emphasis from original).

I'm removing the language about doing this in eastern mass; not only is it not convention, it's probably citation worthy.

--66.92.73.217 (talk) 15:12, 16 May 2010 (UTC)

Yellow vs Amber
Which term is correct? —Preceding unsigned comment added by Shcha (talk • contribs) 15:14, 9 July 2010 (UTC)
 * It depends on where in the world you are. In the UK, it's always "amber" - the only people who call it "yellow" are children who haven't learned the correct name of the colour.  But in the US, I believe "yellow" is the standard term.  But you could well ask which form the article should use generally.  To my British eyes the beginning section doesn't look right at all because of this.  But Americans might claim the reverse.  In any case, the article certainly ought to address the distinction. -- Smjg (talk) 11:24, 6 September 2010 (UTC)

'Robots' or 'semaphore'?
Where in the world are traffic lights commonly known as 'robots or semaphore' per the first sentence? I propose that this is nonsense, and so, since it is unreferenced, I shall remove it. If anyone has citations for those common usages, let them re-add them. --Nigelj (talk) 12:13, 26 July 2010 (UTC)

Manual Control
I haven't seen any information about manual control of traffic lights (maybe I just missed it somewhere?). Granted, my experience comes from working for a fire department in Pennsylvania, so I have no idea whether manual control is commonly available in other parts of the country or other parts of the world. In PA, most (if not all) intersections governed by a traffic light have a manual control box which can be accessed by emergency personnel. The controls allow someone to operate the traffic lights manually by advancing its normal cycle only when a button is pressed, allowing for longer green lights in a certain direction if necessary. The controls also allow the intersection to be switched to "flash" mode where the major roadway flashes amber and the side-streets flash red, allowing for people to direct the intersection by hand without causing confusion by conflicting with red or green lights. There is also the ability to shut the traffic lights off completely. I could actually take a photo of the control switches, but I'm rather new to editing articles on Wikipedia so I'm not sure where I should start. Delvareus (talk) 04:04, 4 November 2010 (UTC)

Two problems with Garrett Morgan section
''In 1923, Garrett Morgan patented his own version. The Morgan traffic signal was a T-shaped pole unit that featured three hand-cranked positions: Stop, in all -directional stop position. This third position halted traffic in all directions to allow pedestrians to cross streets more safely. Its one "advantage" over others of its type was the ability to operate it from a distance using a mechanical linkage.[14]''

1) The bit in bold doesn't make sense, seems to be an incomplete sentence.

2) Reference 14 just leads to another Wikipedia page, and the linked-to section is "Citation required". That's Lessthanideal (talk) 12:45, 4 June 2011 (UTC)

Light colours
" (And indeed, many "green" traffic lights have blue lenses with a yellowish bulb behind them, the combination yielding a green color.)"

Since when does blue light and yellow light make green light? Green is a primary light colour, you don't get it by mixing blue with yellow. —Preceding unsigned comment added by 82.25.174.63 (talk) 18:52, 20 January 2011 (UTC)


 * A filter absorbs light of certain wavelengths while allowing others to pass through - it doesn't combine light colours. So this would work if the yellow light is composed of red light and green light (rather than spectral yellow), and the filter is cyan rather than what would be called blue in technical contexts.  But still, I wouldn't expect traffic lights to really work this way. -- Smjg (talk) 19:31, 20 January 2011 (UTC)


 * Interesting theory. But if you conduct a simple experiment at home you'll see that it works. How is this debate relevant to the article? If sources are cited than those sources are to be believed, no? Slidersv (talk) 18:07, 27 September 2011 (UTC)

red above green and vice versa
Currently the article states that railway signals are intentionally opposite road signals so the two don't get confused.

Disregarding the actual likelihood of them being confused, I've always been understood (but don't have time to search for references atm) that the reasons are independent of each other, i.e. road signals have red on top, because this is the most important aspect, and having it on top minimises the times it will be obscured by other vehicles between it and the driver. On railways, where there is only one train in the section this is not relevant, and so red is placed at the bottom - either because it is closest to the driver's line of vision, or because it will not be obscured by snow accumulating ontop of the lens hood for the aspect below it (as there isn't one). Thryduulf (talk) 14:11, 3 May 2011 (UTC)


 * In Czech Republic, the red light on the railroads is on top. Therefore this explanation would be region-specific Slidersv (talk) 18:07, 27 September 2011 (UTC)

Removal of traffic lights in Europe
This newspaper report from 2006 could be of interest. There's since been a similar (though less extensive) scheme in Portishead, UK. I'll research further news items for possible inclusion in the article when I find the time. --Trevj (talk) 08:05, 8 August 2011 (UTC)

Merging lights
These lights are installed (at least in US) in the places of busy merging lanes. Usually one car per green light. They supposedly make traffic more smooth, however it's not obvious. Article should mention these, should explain why they are needed and how they work, if they do. Yurivict (talk) 23:31, 30 November 2011 (UTC)


 * See Ramp meter.--Triskele Jim (talk) 17:14, 1 December 2011 (UTC)


 * Added ramp meter as "see also" per your suggestion. Thanks. Student7 (talk) 00:59, 5 December 2011 (UTC)

Rewriting Pedestrian and cyclist crossing lights
I think the parts of this section need to be cleaned up. They are confusing and explained horribly in my opinion, this needs clean up badly! — Preceding unsigned comment added by JDOG555 (talk • contribs) 23:31, 2 December 2011 (UTC)

Entering on Yellow, right to proceed
It seems to me that the rules of the road section is rather unclear, with a mish-mash of local information but no authoritative perspective. In particular, I came by to check yellow light rules and was somewhat taken aback by the Ontario reference. Many US states have adopted uniform traffic rules which include the ability to proceed if one enters an intersection while the light is yellow. Citing page 14 of the Kentucky Drivers' Handbook (KY is a recent adopter of uniform rules): "YELLOW A yellow light means the traffic signal is about to turn red. Stop if you can do so safely. A vehicle may clear an intersection on a red light, if the vehicle entered the intersection while the signal was yellow; but it is against the law to enter an intersection after the light turns red. " Some cleanup and clarification seems needed here. KenThomas (talk) 21:24, 13 March 2012 (UTC)

Suggestion for improvement (sensors)
A quick search in WP didn't find an answer to "How are waiting vehicles detected for traffic light changes?"

From http://auto.howstuffworks.com/car-driving-safety/safety-regulatory-devices/question234.htm --

"Let's say you take a coil of wire perhaps 5 feet in diameter, containing five or six loops of wire. You cut some grooves in a road and place the coil in the grooves. You attach an inductance meter to the coil and see what the inductance of the coil is. Now you park a car over the coil and check the inductance again. The inductance will be much larger because of the large steel object positioned in the loop's magnetic field. The car parked over the coil is acting like the core of the inductor, and its presence changes the inductance of the coil. A traffic light sensor uses the loop in that same way. It constantly tests the inductance of the loop in the road, and when the inductance rises, it knows there is a car waiting!"

-- Jo3sampl (talk) 18:05, 30 May 2012 (UTC)

It's commonly believed that loop sensors work by measuring inductance, but this is not true. They work by detecting the "shorted turn" which a vehicle or bicycle imposes. For instance, a bicycle as 3 shorted turns: the frame inside triangle, and the two wheels. But that is outside the scope of this article anyway.

Aspects?
The article talks about "aspects", but doesn't say what an aspect is. 108.213.76.24 (talk) 21:57, 9 May 2013 (UTC)

Where the lights are placed in the intersection
I did not see any information on different where different placed place their trafic lights. I know that where I am from, the lights are placed on the far side of the crossing road, but, at least in NYC, they are placed on the closer side, above the heads of the people waiting closest to the intersection. Is there any info on why there is different placement locations in different locales? 63.140.104.240 (talk) 18:50, 23 May 2013 (UTC)

Orange?
I'm not sure where all the references to orange came from for yellow lights. In the US, "Portland orange" is used for don't walk indications, but that's it. I removed many of them, but left the ones under "Pedestrian crossings/European standard" since I'm not familiar with European crosswalk signals.

Much of that section appears to be talking about vehicle signals, but I'm not sure, so I left it for now.--Triskele Jim 17:09, 5 July 2014 (UTC)


 * In the U.K., people sometimes use orange when talking about traffic lights, but amber is the more usual term, and is the word used throughout the applicable legislation. Yellow tends to be used only in traffic engineering circles.  74.42.185.35 (talk) 04:16, 15 May 2015 (UTC)

Red on top -- placement of lights
The article never mentions, or I never saw it, the placement of the colors, with red on top, green below, and amber in the middle. Standardization is always desirable in traffic control devices, for the reason that drivers know what to expect no matter where they are driving. Another feature served by the standard positioning is to make driving possible for that segment of the population with red-green color blindness. Color blindness is fairly common in males across the world. I studied traffic engineering long ago, and am not up on the latest sources for what I learned back then. In the color blindness article, one nation is mentioned as barring driving by those with any form of color blindness. I do not believe the eye tests used for driver licenses world wide, or US-wide, bar all with red-green color blindness from driving, because of the standard position of the colors, even on signals organized horizontally (as red is always in the same place on all the horizontal lights). That point may be minor compared to the overall benefits of standard placement of the colors; but placement of the colors is worth a mention. --Prairieplant (talk) 05:24, 5 August 2015 (UTC)
 * Take a look at Traffic light.  Etamni &#124;  &#9993;  05:33, 5 August 2015 (UTC)
 * Thanks, I was about to delete my comment. I made Types its own section, and revised the title to include placement. Pedestrian signals is its own section, as well. I put a simple definition of the term Aspect, mentioned in a comment above. There remains no explanation of why standardization is important in traffic signals; it remains an unspoken assumption. --Prairieplant (talk) 06:44, 5 August 2015 (UTC)

Possible copy-paste
The section on turning signals has generally identical text to this article http://www.ledesl.com/08-12-2009/traffic-turning-signals-and-rules.html, with minimal references or wikification. Could this be an example of a copy-paste plagiarism? Or is it more likely that this website has just lifted the text from wikipedia? Nren4237 (talk) 07:06, 5 August 2015 (UTC)
 * Good catch. The other article copied Wikipedia.  This can be confirmed by the fact that the content was in Wikipedia well before the date of the other article; the other site has references to images that the article states are shown "above," but which aren't in the other article, and are still in Wikipedia; and finally, if you look at the page source (i.e. the raw HTML) on the other page, you will see that certain Wikipedia codes were not removed, even though the other web page doesn't know how to render them.   Etamni &#124;  &#9993;  08:25, 5 August 2015 (UTC)
 * Thanks for clearing this up! Nren4237 (talk) 10:05, 5 August 2015... (UTC)

Poor picture selection
The historical introduction is devoid of images of historical traffic lights. There are many at http://streets.mn/2014/10/29/traffic-signal-trivia/

I also recall from the 1950s, in German villages, lights hanging above the center of intersection, with only two light bulbs: red-above-green in one direction, and green-above-red in the other direction. A disaster for color-blind drivers. I wish I had a picture. GioCM (talk) 17:00, 5 August 2015 (UTC)

Semi-protected edit request on 5 August 2015
The mention of the word freeway should perhaps be prefixed with US to indicate to world readers that this is referring to USA. Other countries use Autobahns, Autostradas and Motorways but it is the US freeways that seem to use lights on on-ramps.

50.71.122.123 (talk) 14:37, 5 August 2015 (UTC)
 * Red question icon with gradient background.svg Not done: it's not clear what changes you want to be made. Please mention the specific changes in a "change X to Y" format. Ivanvector 🍁 (talk) 18:45, 5 August 2015 (UTC)
 * I understand what the IP user was requested and have modified the section accordingly. The concern was the use of the US-centric term "freeway" to refer to a controlled-access highway.  The term has been changed to be less US-centric, and the section it appeared in has been adjusted slightly to include a link to the separate ramp meter article as well.   Etamni &#124;  &#9993;  01:03, 6 August 2015 (UTC)

Semi-protected edit request on 5 August 2015
Sun, 1877-03-04


 * On this date, in 1877, we mark the birth of Garrett Augustus Morgan. He was an African American businessman and inventor.

The son of former slaves, Garrett Morgan was born in Paris, Kentucky, his early childhood was spent attending school and working on the family farm. In 1895, Morgan moved to Cleveland, where he went to work as a sewing machine repair man for a clothing manufacturer; he opened his own shop in 1907. The company turned out coats, suits, and dresses, all sewn with equipment that Morgan himself had made. In 1920, Morgan moved into the newspaper business establishing the Cleveland Call.

His curiosity and innovation led to the development of many useful and helpful products. Among his inventions was an early traffic signal. After witnessing a collision between an automobile and a horse-drawn carriage, Morgan was convinced that something should be done to improve traffic safety. Morgan was one of the first to apply for and acquire a U.S. patent for a traffic signal. The patent was granted on November 20, 1923. Morgan later had the technology patented in Great Britain and Canada. He also invented a zigzag stitching attachment for manually operated sewing machine. In 1916, Morgan made national news for using a gas mask he had invented to rescue several men trapped during an explosion in an underground tunnel beneath Lake Erie. After the rescue, Morgan’s company received requests from fire departments around the country that wished to purchase the new masks.

The Morgan gas mask was later refined for use by U.S. Army during World War I in 1921. As word of Morgan’s life-saving inventions spread across North America and England, demand for these products grew. He was frequently invited to conventions and public exhibitions to demonstrate how his inventions worked. Garrett A. Morgan died on August 27, 1963, at the age of 86. His life was long and full, and his creative energies have given us a marvelous and lasting legacy.

PLEASE GIVE CREDIT — Preceding unsigned comment added by 167.206.67.209 (talk) 12:22, 5 August 2015 (UTC)


 * Not sure what is being asked here, but Garrett Augustus Morgan has his own page and does not need biographical info added to the traffic light article. Today is NOT his birthday.  Proper citations for the traffic light information were not provided, but if you want to provide those, that information could certainly be added to the article.   Etamni &#124;  &#9993;  01:13, 6 August 2015 (UTC)

First electrical version?
Could someone advise which part of this article has the right of it? The opening states "The first safe, automatic electric traffic lights were installed in the United States in the late 1890s" then a little further it is said that "The first electric traffic light was developed in 1912 by Lester Wire, a policeman in Salt Lake City, Utah, who also used red-green lights". I am unable to read the source for the '1890's' claim, but clearly the two sentences contradict, the first electrical versions cannot have been installed in the 1890s if they were not even invented until 1912.176.248.27.2 (talk) 20:35, 25 May 2016 (UTC)
 * I changed the first statement to resolve the conflicting facts and replaced the foreign-language source with a non-conflicting and readable source, hope it helps! Sam.gov (talk) 21:30, 25 May 2016 (UTC)

That helps, thanks, so it was 1912, I guess some crossed wires with the 1890s thing176.248.27.2 (talk) 21:37, 8 June 2016 (UTC)

Pedestrian scramble
Hi Hameltion. Others, please see history for how scramble was linked.

I think scramble should be linked in a place and way that it can be found. Somewhere in the Australia and New Zealand subsection doesn't serve visitors. It is hidden there, and also scrambles are something that exists around the world, not just in Australia and New Zealand. How should we handle this? Personally, I like this version. Cheers. Anna Frodesiak (talk) 18:34, 18 July 2017 (UTC)


 * Okay. That looks good, you just might want to put it like this:




 * Another option is turning it into prose, and adding another paragraph. Sorry about undoing it. --Hameltion (speak, spoken) 18:41, 18 July 2017 (UTC)


 * Hi Hameltion. Not at all, my friend. Wikipedia is much ado about doing and undoing.


 * I like your suggestions. Your call. Please do make the edit how you wish. All the best. Anna Frodesiak (talk) 18:52, 18 July 2017 (UTC)

Spelling variety
The variety of English used in this article is inconsistent: It uses the British "colour" but also the American "offense". According to the banner on this talk page, British English is used, so I'm going to try to standardize (standardise?) it to that. Or if there is a reason to favour (favor?) American English, that's fine too, but let's be consistent. Heimstern Läufer (talk) 12:18, 7 December 2017 (UTC)

Flashing Green Light
In some parts of the world, a flashing green light means that the light is stale and will change to orange within (usually) 10 seconds.

I have seen this in several cities in British Columbia, Canada. However, I do not know where else it is used. Drbits (talk) 01:04, 5 April 2018 (UTC)

Flyer22 Reborn
Hello "Flyer22 Reborn",

I have just seen your change: "14:29, 6 July 2019 diff hist -2,596‎ m Traffic light ‎ Reverted".

I am not sure to have a clear understanding of the issue. could you provide comment? — Preceding unsigned comment added by 86.67.188.208 (talk) 15:02, 6 July 2019 (UTC)

Engvar
Why is this article listed as British english? The first edits that used the word to specify the visualization of a wavelength of light used the american word 'color' rather than the other spelling 'colour'. https://en.wikipedia.org/w/index.php?title=Traffic_light&direction=next&oldid=1260192

I imagine that the article should be changed, as is in the MOS for Wikipedia? Cheers 90.207.171.217 (talk) 22:06, 12 August 2019 (UTC)

About Traffic Lights
What is traffic light that is used for car racing called? I'm curious. --DukeyDukeyDoo (talk) 01:32, 2 March 2020 (UTC)

Green changed to turquoise
Despite still being commonly referred to the 'green light', the green color was phased out during the 2010s (here in the UK) and all LED traffic lights now use a blue-turquoise light (apparently to assist colorblind drivers who struggle to see the difference between red, amber, and green). The curious fact that it is still called 'green' while not actually being green is surely worthy of inclusion in the article? I added this detail but it was removed? Thoughts on this? Grand Dizzy (talk) 16:39, 2 June 2020 (UTC)
 * it was removed because it wasn't sourced. If it is as you say, then you should be able to find plenty of reliable sources to support it. -- DeFacto (talk). 16:55, 2 June 2020 (UTC)
 * Thank you, I will find a source and include it in the article. Grand Dizzy (talk) 18:04, 2 June 2020 (UTC)

terminology yellow - amber - orange
The article uses mostly the term orange when refering to the third colour usually between green and red. Even if the colour used appears darker or more reddish than pure yellow, in most cases amber would be the better reference to the actual colour. But then formally speaking, even this is at least questionable and sometimes explicitly wrong. For example, German Traffic rules explicity refer to it as Yellow. — Preceding unsigned comment added by 24.134.162.73 (talk) 09:59, 13 October 2020 (UTC)

The US uses a standard set of colours for all traffic control devices (signs and lights). These are defined in the Manual of Uniform Traffic Control Devices, Section 1A.12. Those colors are:

″ Standard: The general meaning of the 13 colors shall be as follows: A. Black—regulation B. Blue—road user services guidance, tourist information, and evacuation route C. Brown—recreational and cultural interest area guidance D. Coral—unassigned E. Fluorescent Pink—incident management F. Fluorescent Yellow-Green—pedestrian warning, bicycle warning, playground warning, school bus and school warning G. Green—indicated movements permitted, direction guidance H. Light Blue—unassigned I. Orange—temporary traffic control J. Purple—lanes restricted to use only by vehicles with registered electronic toll collection (ETC) accounts K. Red—stop or prohibition L. White—regulation M. Yellow—warning ″

U.S. traffic lights use red, yellow and green. An orange light would be for temporary traffic control (usually related to construction) and would not be used in a traffic light.

Britain uses the term yellow for traffic signage in Traffic Signs Manual, Chapter 1, Introduction 2018, Appendix A, yet uses Amber in describing traffic signals. In Traffic Signs Manual, Chapter 6, Traffic Control 2019, Appendix A, Amber is defined as "Amber: The particular colour in the yellow part of the spectrum used in traffic signals. The same as the term “yellow” used in European specifications″

I propose that yellow be used as the primary term, with reference to amber as used in some locales. And orange should never be used (unless it is accurate for the Tram section). 140.194.140.56 (talk) 15:54, 29 October 2020 (UTC) John Griffin

Regardless of the mention of Amber I referenced above (Traffic Signs Manual, Chapter 6, Traffic Control 2019, Appendix A), amber might not be formally correct in the United Kingdom. In a preview version of BSI Standards Publication, Traffic control equipment — Signal heads, BS EN 12368:2015, the Scope paragraph refers to ″This European Standard applies to signal heads with one or more signal lights of the colours red, yellow and/or green signal lights for road traffic...″. 140.194.140.56 (talk) 18:06, 29 October 2020 (UTC) John Griffin

Bisi alareno
Traffic light are signal that are on the road to slow traffic Bisi alareno (talk) 09:19, 15 November 2021 (UTC)