At the moment, I'm driving around in Québec. I've noticed that the green traffic light can be blinking or constant. I assumed that I'm allowed to drive in both situations. However, is there any difference? My first guess was that the blinking light indicates that I have to be careful when left turning because of traffic from the opposite direction, but this does not always to be true.

So what exactly is the difference?

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    you didn't notice them in Vancouver as well? ;)
    – Mark Mayo
    Commented Aug 27, 2012 at 16:47
  • Your post reminded me of the first time I came across a flashing yellow light. I had no clue! I grew up in Southern California and we have the occasional flashing red light, or even no light at all if the power is out, but very rarely a flashing yellow. I first came across one in San Francisco and had to ask my friend what it meant. I would also be confused by flashing green. Thanks for the post, I learned something today! :)
    – MrOBrian
    Commented Aug 27, 2012 at 20:49

6 Answers 6


In Québec, a flashing green traffic light means that no cross-traffic can go, even the traffic on the same road coming from the other direction has a red light. This means that (if allowed) you can make a left turn without having to yield (except possibly to pedestrians in the cross street). See e.g. this or this advice on the peculiarities of driving in Québec.

This is apparently purely indicative since the Québec traffic code doesn't distinguish flashing and solid green lights (§363).

Note that in some other Canadian provinces, such as British Columbia, flashing green lights have a different meaning which allows cross-traffic.

On a related topic, note that a flashing red indicates that you must mark a stop, but may then proceed after yielding to all traffic that reached the intersection ahead of you: a flashing red is equivalent to a stop sign. On a solid red, you must wait for the light to change. As an exception, in Québec like in most of North America, you may make a right turn on a solid red after marking a stop and yielding to all traffic; however some municipalities forbid right turns on red.

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    A note on turning on a red: I live in Southern California and it's also legal to turn left on a red if you are going from a one-way street to another one-way street, as long as we yield right-of-way to cross traffic and pedestrians.
    – MrOBrian
    Commented Aug 27, 2012 at 20:45
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    The island of Montreal is one of the places where you can't turn on red.
    – Jonas
    Commented Aug 27, 2012 at 22:23
  • @MrOBrian New York City notably bans right turns on red unless specifically posted, which it is in a few places, plus in at least one location (39th and 1st, if I remember correctly) there is a specifically posted legal left on red for a similar situation. Of course, one-way to one-way is the norm in NYC, but general traffic levels (particularly pedestrian traffic) make rights on red unfeasible.
    – KRyan
    Commented Jun 15, 2014 at 7:45
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    Bit OT, but here in Qatar, green lights flash for three seconds ( three on/offs, one every second) just before they are changing to yellow (yellow stays on for 3 seconds), and then to red.
    – DavChana
    Commented Jan 14, 2016 at 2:34
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    @DavChana the same is true in some southern European countries, though the timing seems to vary depending on the speed limit. There is also a phase between red and green where both the red and yellow lights are on, so you have a chance to put your car in gear or otherwise prepare to start driving.
    – phoog
    Commented Aug 19, 2017 at 12:26

In Ontario, pretty much all of the flashing greens have been replaced with green arrows. When we had flashing greens, they were inevitably accompanied by a sign "advanced green when flashing". This referred to the fact that you were getting the green in advance of the traffic moving towards you, and so could freely turn left (or go straight.) Some intersections had "delayed green when flashing".

enter image description here Image source: Flickr, licensed under CC BY-NC-ND 2.0

The photo license won't let me crop it to just the light. Says it was taken this summer, so some of these are still around I guess.

Since you need to both read English and know what "Advanced Green" refers to, these have mostly been replaced with a green arrow, which is probably safer. (Page 16 of Ontario Traffic Manual, Book 12 – Traffic Signals (PDF) says they are being phased out as of July 2010. It's not aimed at drivers, but makes for interesting reading.)

Don't assume you know what a flashing green means in another province: look for a sign.

  • Still plenty of flashing green lights around in Ontario. Commented Aug 27, 2012 at 16:16
  • Further, "advanced greens" in Ontario always mean the cross pedestrian traffic still has their don't-walk phase, so there ought not to be pedestrians to conflict with. In reality a lot of pedestrians see the green traffic light and barge out, so be careful.
    – CCTO
    Commented Apr 17, 2018 at 16:32

I know you asked about Quebec but I think it's useful to point out that blinking can mean wildly different things:

In Austria, a green traffic light will blink green four times before switching to yellow and red.

This is meant as a pre-warning to avoid people driving through "dark yellow". Austrian drivers know this and will usually stop at yellow (not red). They will also honk angrily at people who brake at blinking green. Drivers who don't know this Austrian specialty are thoroughly confused.

It's also worth mentioning that, in Austria, the duration of the yellow phase (before red) is always the same length -- opposed to for instance Denmark, where the yellow phase is much longer in complicated intersections because the traffic planners know that it takes longer to clear the intersection before the next traffic direction can start.

The green arrows mentioned in another answer exist in both Austria and Denmark; presumably throughout Europe. But even though many traffic signs have been standardized across Europe (or the EU, whatever) it is evident that many exceptions still exist. Standards... sigh.

(I'm from Denmark but live in Austria. I prefer the Danish method because it varies on a case-by-case basis, sometimes even depending on the time of day or on traffic sensors in the lanes.)

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    The flashing green before a yellow is an interesting idea. I wonder how much it helps to reduce accidents caused by people running red lights. Another idea I liked was when I visited London and their traffic lights change to red and yellow (both on at the same time) just before turning green, giving drivers enough warning to, for instance, put manual transmission cars in gear.
    – MrOBrian
    Commented Aug 27, 2012 at 20:54
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    At least in Europe this is consistent across each country. Unlike in North America where driving rules vary not only by state but even by municipality! Commented Aug 27, 2012 at 20:55
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    @MrOBrian: Red+yellow combined is standard across Europe. I've also seen it in Japan (and, I think, Australia). Are you saying that doesn't exist in USA? Does it just jump from red to green? BTW, people who drive manually (which is the standard in Europe) put their car in gear much sooner; then just keep the clutch pressed until it's time to go. Commented Aug 27, 2012 at 21:00
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    @TorbenGundtofte-Bruun Red+yellow doesn't exist in France nor in Mediterranean countries or in the Benelux. Wikipedia has a list, I don't know how complete it is. Commented Aug 27, 2012 at 21:07
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    @Gilles: Doesn't look complete; it only gives some examples. At least all Nordic countries have red+yellow before green. Btw, related question on the UX site.
    – Jonik
    Commented Aug 28, 2012 at 5:50

Apart from Quebec, a flashing green light has a different meaning in Turkey (and possibly in some other European countries).

At some point during the night (usually around 2am), the lights switch to blinking mode to show the right of way to drivers. All lights in an intersection goes to blinking mode in red, yellow or green and the colors don't change. This is for not making drivers wait in a long red light where there's no traffic.

Blinking green means you have the right of way, but use caution as some wreckless driver may not see you.

Blinking yellow is equal to yield sign.

Blinking red is equal to stop sign.

  • In the US (in my experience, at least, which is mostly in the northeast), we have the same, except that there's no blinking green. At a 4-way intersection, you either have blinking red all around, or blinking red on one road and blinking yellow on the other. The meanings of blinking yellow and blinking red are the same, equivalent to a yield sign and stop sign, respectively.
    – phoog
    Commented Dec 28, 2015 at 23:27
  • Actually, in the US and Canada, it is not the case that blinking yellow equals yield. Rather, flashing yellow is a general indication of a hazardous location at which extra caution is warranted. For example, it's very common where a minor road crosses a major one, to have the cross street posted with stop signs and flashing red, and the main road (which has no stop or yield) to have a flashing yellow. You cannot have one direction stop and the other yield; that would be a deadlock. It's either all-way stop, or else cross traffic stops (or yields) to a right-of-way.
    – CCTO
    Commented Apr 17, 2018 at 16:36
  • @CCTO: I suspect part of the purpose of flashing yellow in the USA is to indicate to the driver that the intersection doesn't have a broken signal light that would--if noticed by a motorist--need to be treated as a four way stop.
    – supercat
    Commented Nov 13, 2023 at 19:12

Massachusetts has these, though they are rare and being phased out. They indicate a crosswalk with a signal that can be controlled by pedestrians. They are intended to warn drivers to be prepared to stop/yield for pedestrians. They are generally used at unusual crossings: diagonal, 3-way intersections, 5-way intersections, and are often combined with a yellow and red light that shine solid when a pedestrian requests a walk signal.


Blinking green should be the indication that green light ends and yellow and red appears. It is a usefuk info letting the driver to adjust his driving to the green light end situation, hence no need for hard braking when approaching the intersection.

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    Welcome! The other answers make it clear that blinking green lights can have radically different meanings in different places. You don't say where your answer applies and you don't give any evidence beyond your own word, so this answer isn't very useful. Commented Dec 29, 2015 at 0:56
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    In addition -- not all traffic codes even support flashing greens. (The US MUTCD defines them as meaningless and not to be used for any purpose.) Commented Jan 14, 2016 at 0:16

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