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Double Red Lights (in Saskatoon)

Started by 7/8, April 23, 2017, 11:40:27 PM

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7/8

I've noticed several locations in Saskatoon with two red lights at left-turns. From what I've seen so far, this is used at protected left turns, while a single red light is used at permissive left-turns. I find it cool that the "no left on red" sign shows two red lights as well. I'm curious if anyone else has seen anything like this before.

It's also interesting to me that the "no left on red" sign is even there, since in Ontario, we use a "left turn signal" sign instead. But I think this sign is probably a little more clear than Ontario's way.

Here's a screenshot of GSV at SK 5 EB turning left onto McOrmond Drive. https://www.google.ca/maps/@52.1358557,-106.5531542,3a,15y,44.65h,91.37t/data=!3m6!1e1!3m4!1sXhRcuuEshWq66xWyJPk9DQ!2e0!7i13312!8i6656


MNHighwayMan

It's things like this that really make me wonder why Canada can't be so much more like the United States in standards. FFS, just use a red left arrow. To me, and I imagine a lot of people, that's pretty unambiguous and doesn't require all the extra BS signage.

SignGeek101

#2
They're common (and I believe exclusive) to Saskatchewan. I'm not too sure why they are used instead of a regular setup.

Here are a couple others:
https://goo.gl/maps/kUtjzhtnbMN2
https://goo.gl/maps/eMsF7AykrPt

And how about this:
https://goo.gl/maps/EqabJSAUETx

Quote from: MNHighwayMan on April 23, 2017, 11:45:02 PM
It's things like this that really make me wonder why Canada can't be so much more like the United States in standards. FFS, just use a red left arrow. To me, and I imagine a lot of people, that's pretty unambiguous and doesn't require all the extra BS signage.

Imagine if Canada had a different unit of measure on signs, different languages / bilingualism on signs, and vastly different BGS designs from province to province? Oh wait...  :)

Canada, being a former colony of England, could have used Australia's example of driving on the left and using only white paint on roadways, but instead opted to align itself closer to the US for convenience.

Canada, unlike the US, does not have a national MUTCD (only a "loose" one called Transport Canada that oversees the entire transportation industry i.e. not just roads). Thus, everything is done by the provinces. I really do wish there was more coordination between the provinces though, particularly on signs. The difference in style between BC, Ontario and Quebec are vast.

Also, mods, perhaps this should be moved to the Canada board?




Also, 7/8, if it's possible, you should check out the Regina bypass being built east of the city. It will be new freeway which will be completed by the end of the year.

https://www.saskatchewan.ca/residents/transportation/regina-bypass/regina-bypass-project

7/8

Quote from: SignGeek101 on April 24, 2017, 12:19:56 AM
They're common (and I believe exclusive) to Saskatchewan. I'm not too sure why they are used instead of a regular setup.

Here are a couple others:
https://goo.gl/maps/kUtjzhtnbMN2
https://goo.gl/maps/eMsF7AykrPt

And how about this:
https://goo.gl/maps/EqabJSAUETx

Quote from: MNHighwayMan on April 23, 2017, 11:45:02 PM
It's things like this that really make me wonder why Canada can't be so much more like the United States in standards. FFS, just use a red left arrow. To me, and I imagine a lot of people, that's pretty unambiguous and doesn't require all the extra BS signage.

Imagine if Canada had a different unit of measure on signs, different languages / bilingualism on signs, and vastly different BGS designs from province to province? Oh wait...  :)

Canada, being a former colony of England, could have used Australia's example of driving on the left and using only white paint on roadways, but instead opted to align itself closer to the US for convenience.

Canada, unlike the US, does not have a national MUTCD (only a "loose" one called Transport Canada that oversees the entire transportation industry i.e. not just roads). Thus, everything is done by the provinces. I really do wish there was more coordination between the provinces though, particularly on signs. The difference in style between BC, Ontario and Quebec are vast.

Also, mods, perhaps this should be moved to the Canada board?




Also, 7/8, if it's possible, you should check out the Regina bypass being built east of the city. It will be new freeway which will be completed by the end of the year.

https://www.saskatchewan.ca/residents/transportation/regina-bypass/regina-bypass-project

The third GSV link you posted with the two-head signals is pretty cool. I'm guessing the bottom signal is both a green and yellow area (so people have a heads up that it's changing to red)?

I'll try to find time to see the Regina bypass, but I'm only there for a day, and my friend probably isn't interested. Hopefully he won't mind taking a few minutes to see it.

MNHighwayMan

I still stand by my assertion that Canada could be a little less weird with some stuff. The protected left turns being item number one.

jakeroot

#5
The practice is ubiquitous in Alberta at protected signals (the signs (with four lenses) are common in Edmonton). I've never seen it practised in British Columbia.

Here are some examples (just to provide proof -- all protected lefts in AB use dual reds):

https://goo.gl/6jZE54 (Stoney Plain @ 184 St)
https://goo.gl/Mq0QUJ (178 St @ 87 Ave near the West Edmonton Mall)
https://goo.gl/YQogci (170 St @ 87 Ave)
https://goo.gl/bcChwA (170 St @ 69 Ave)

Quote from: MNHighwayMan on April 24, 2017, 12:46:34 AM
I still stand by my assertion that Canada could be a little less weird with some stuff. The protected left turns being item number one.

Red arrows are used sparingly in Quebec. Though I do agree that the practice would be welcome country-wide.

Example of red arrow in Quebec: https://goo.gl/x3szK3 (Rue Viau @ Sherbrooke St, Montreal)

Eth

I've lately been seeing scattered around (in the US) occasional double red arrows arranged horizontally on top, forming a T-shaped four-head signal. The purpose seems unclear - are they trying to convey, "no, no, seriously, don't turn right now, we REALLY mean it"?

MNHighwayMan

You have an example of that? Now that sounds really interesting (and unusual).

kphoger

Quote from: SignGeek101 on April 24, 2017, 12:19:56 AM
Quote from: MNHighwayMan on April 23, 2017, 11:45:02 PM
It's things like this that really make me wonder why Canada can't be so much more like the United States in standards. FFS, just use a red left arrow. To me, and I imagine a lot of people, that's pretty unambiguous and doesn't require all the extra BS signage.

Imagine if Canada had a different unit of measure on signs, different languages / bilingualism on signs, and vastly different BGS designs from province to province? Oh wait...  :)

Double red lights are also very common in Mexico.  On page 576 of the SCT's Manual de Señalización Vial y Dispositivos de Seguridad 2014 (warning:  link goes to a large .pdf), three of the seven recommended arrangements feature double reds.

Below is a picture I took of one in Mexico back in July.


So maybe the question is, why can't the US be more like both of its neighbors?   :sombrero:
Keep right except to pass.  Yes.  You.
Visit scenic Orleans County, NY!
Male pronouns, please.

Quote from: Philip K. DickIf you can control the meaning of words, you can control the people who must use them.

freebrickproductions

Texas uses (or at least used) double reds on its left turn signals. South Carolina does the same, but with red arrows in a T-shaped head.
It's all fun & games until someone summons Cthulhu and brings about the end of the world.

I also collect traffic lights, road signs, fans, and railroad crossing equipment.

(They/Them)

SignGeek101

Quote from: freebrickproductions on April 24, 2017, 08:29:18 PM
Texas uses (or at least used) double reds on its left turn signals.

Here's an old post about it:

Quote from: US71 on May 09, 2011, 05:08:01 PM
Most Flashing Yellow Arrow signals use a Red Arrow.

Texas has a hit & miss attitude to Red Arrows: some signals have them, many don't.

Paris, TX uses a Double Red Ball for their left turn signals



As does Lumberton


AsphaltPlanet

#11
It's things like this that really make me wonder why the United States can't be so much more like Canada in standards. FFS, just use a double red ball. To me, and I imagine a lot of people, that's pretty unambiguous and doesn't require all the extra BS signage.
AsphaltPlanet.ca  Youtube -- Opinions expressed reflect the viewpoints of others.

MisterSG1

Well, I've always wondered why the MTO hasn't considered using the red left arrow, consider why I think it's a no brainer that they should use it, one simple word, that the MTO is obsessed with.

Bilingualism

With a red left arrow, it makes it obvious in all languages what the red arrow is for, indeed I have seen bilingual versions of the "LEFT TURN SIGNAL" sign, but in the GTA you won't find any at all.

For those that say legal work makes it tough to change, not necessarily, as of Jan 1, in Ontario, red/yellow/green bike pictogram signals are allowed for bicycle signals, so there is no reason why they couldn't in theory apply this to fully protected left turn signals.

AsphaltPlanet

^ If I were to guess at why the MTO has never adopted red arrows within traffic signals it is that they are significantly less visible than a standard red ball.  Consider for a second the relatively small amount of the traffic signal lens that is illuminated by the red arrow compared to a red ball.  A red arrow illuminates what 30% of the signal lens?  Certainly other jurisdictions do different things, but a red arrow is by now means a perfect way to show a protected left either.
AsphaltPlanet.ca  Youtube -- Opinions expressed reflect the viewpoints of others.

MisterSG1

I'm not sure that I totally buy that argument, although rarely found, we both know that legally, red ball signals in Ontario can have a diameter of only 20cm or 8 inches. When one compares one to the other, I think it's honestly safe to say at a distance that the 30cm arrow illuminates better than the 20cm ball. Perhaps this is why all arrow signals have to be 30cm?

AsphaltPlanet

20cm red ball traffic signals haven't been installed in decades.  And even when they were common, it was only the auxilliary signal heads that were allowed to feature a 20cm red signal lens.

There is no argument that the red arrow is much less pronounced on this traffic signal than it is on a green signal:



There are absolutely counter-arguments of why this is a good signal configuration, but you can't argue that the red arrow is nearly as visible as a full 30cm red ball.

AsphaltPlanet.ca  Youtube -- Opinions expressed reflect the viewpoints of others.

Revive 755

^ A modern LED Red Arrow is visible enough to be made out from a decent distance - I can think of a few that are visible from over a 1000 feet away.  For the above photo, the red arrow is being cut off partially by the signal visor, and I'm sure the lesser viewing cone for LED indications is also helping dim the arrow based on the camera position.

AsphaltPlanet

Right, but can you honestly say that an LED signal where only 30% of the traffic signal is illuminated would be as visible as a signal where 100% of the traffic signal is illuminated?  Of course not.

Now, I'm not saying that the pictured configuration is really a problem or a bad design, but, that being said, I can definitely see whey a jurisdiction may not wish to use a signal head where so little of the head is illuminated, particularly at times of poor visibility, such as in fog, or a significant snow or rain storm.
AsphaltPlanet.ca  Youtube -- Opinions expressed reflect the viewpoints of others.

jakeroot

Quote from: AsphaltPlanet on April 24, 2017, 10:03:13 PM
Right, but can you honestly say that an LED signal where only 30% of the traffic signal is illuminated would be as visible as a signal where 100% of the traffic signal is illuminated?

Keep in mind what you just responded to:

Quote from: Revive 755 on April 24, 2017, 09:54:06 PM
A modern LED Red Arrow is visible enough to be made out from a decent distance - I can think of a few that are visible from over a 1000 feet away.

Why do you (AsphaltPlanet) need to see a left turn signal from so far away? It only matters when you enter the left turn lane.

Canada does a lot of things well. This "LEFT TURN SIGNAL" business is not one of those things.

Jet380

Perhaps the double red ball is a redundancy treatment to avoid creating a dangerous situation if one of the bulbs goes out. This would be important for some of these intersections as it looks like only one left turn signal head is provided. Otherwise all it would take is one bad bulb and there is no cue for turning traffic.

I don't really see any visibility issue with using arrows though. In most cases drivers should be slowing down to make a turn anyway! Hell, in Australia we manage with 20cm arrow lenses  :D

AsphaltPlanet

In my expectation, I would make the assumption that slightly more drivers would fail to observe a red arrow compared to a full red ball.  Consider that, even though there shouldn't be, there are drivers who have imperfect vision, may be over tired, may be impaired with either drugs or alcohol.  Having a signal head where less of it is illuminated is unquestionably less visible than a full signal-ball.  Now the consequences of a driver failing to see a signal head for a protected left turn isn't too grave.  Presumably, most drivers who fail to notice the signal (and I wouldn't expect their to be that many), would treat the left turn as a permissive left, and make a safe left turn.  That being said however, it is my expectation that any engineer who installs a fully protected left turn signal does so for a rationale with good engineering judgement that suggests that a fully protected left will operate more safely than a permissive condition, for one of a variety of reasons, so, I would expect a very, very slight increase to the accident expectancy rate for the intersection based on these facts.

Now, consider an alternative option, using either one or two red balls.  My expectation would be that a slightly lower percentage of drivers would fail to see the signal head, however that may be offset by a very slight increase in the number of drivers who don't interpret the traffic signal correctly, as it is slightly more ambiguous than a red arrow.

So, my point is (and always has been), that you swap one (albeit very small) problem for another when choosing different traffic signal head designs, but I don't think anyone could really say that one is better than the other.  Both work traffic signal scenarios would work adequately most of the time, but neither design is perfect.

I'd challenge someone who argues that the left arrow is indeed superior to back that up with actual crash statistics to support their position, otherwise I don't think it's fair to say that the design is actually better based on empirical data.
AsphaltPlanet.ca  Youtube -- Opinions expressed reflect the viewpoints of others.

kphoger

Quote from: AsphaltPlanet on April 25, 2017, 09:46:11 AM
Having a signal head where less of it is illuminated is unquestionably less visible than a full signal-ball.

But, if both are sufficiently visible at a sufficient distance, then it doesn't matter which one is more or less visible.  After all, a 36-inch ball would be unquestionably more visible than what we have today, but that does not necessarily mean it would make any actual difference.
Keep right except to pass.  Yes.  You.
Visit scenic Orleans County, NY!
Male pronouns, please.

Quote from: Philip K. DickIf you can control the meaning of words, you can control the people who must use them.

AsphaltPlanet

I'd wager that both options are sufficiently visible in most situations.  But, I'd also argue that there are a few scenarios where a full red ball is advantageous to a red arrow, specifically in times of low visibility, and for drivers who may be tired, impaired or distracted.  And therein lies the trade-off, is it better for a signal to be the most visible as possible, or is it better for the message to be clearer, at the cost of some visibility.  My post outlines why I am not of the opinion that either situation is really inherently better.

One could argue that a 20cm traffic signal lens is probably sufficiently visible most of the time too.  However, given that (to my knowledge), no North American jurisdiction still uses 20cm signal heads on new installations, there is probably some empirical evidence to suggest that while a 20cm signal head may be sometimes acceptable, it is not as desirable as a 30cm signal head.

Because there are so many different jurisdictions that use another solution, rather than a red arrow signal head, to denote a protected left turn, I would argue that there isn't any empirical evidence that suggests one solution really is all that advantageous to another.
AsphaltPlanet.ca  Youtube -- Opinions expressed reflect the viewpoints of others.

jakeroot

#23
Quote from: AsphaltPlanet on April 25, 2017, 01:42:14 PM
One could argue that a 20cm traffic signal lens is probably sufficiently visible most of the time too.  However, given that (to my knowledge), no North American jurisdiction still uses 20cm signal heads on new installations, there is probably some empirical evidence to suggest that while a 20cm signal head may be sometimes acceptable, it is not as desirable as a 30cm signal head.

The FHWA permits 20 cm signal heads if the signal head is less than 120 feet from the stop line (from what I could extract from the link just before), though the recommendation is just to use 30 cm signal heads all the time. Overall, very few agencies still install 20 cm signal heads (Seattle is one place that I still see it, as well as New York).

British Columbia is probably the only place left in North America that actually recommends 20 cm signal heads, depending on where the signal is installed. See page 86-87 from this PDF for a full guide. From my experience, near-side protected left turn signal heads are about half and half 20-20-20 or 20-20-30 (third lens is green arrow). Auxiliary signal heads (on the masts, both near and far) are often 20-20-20, or 20-20-20-30 if there's a bi-modal arrow lens at the bottom. 30 cm signal heads for all signals in an intersection are not uncommon, but have (wait for it) mostly fallen out of favour. They used to be more common, but newer installations are mostly a mix of 20 and 30 cm signal heads.

Here's an example that I drew up a while back of a typical intersection setup. Measurements are obviously imperial. The intersection itself is relatively new.


kphoger

Quote from: Brandon on April 27, 2017, 05:41:58 PM
Who really gives a crap what is on the signs as long as it is consistent within a county?

People whose cars don't have mph on the speedometer (such as might be in a Canadian or Mexican vehicle driven into the US).
Keep right except to pass.  Yes.  You.
Visit scenic Orleans County, NY!
Male pronouns, please.

Quote from: Philip K. DickIf you can control the meaning of words, you can control the people who must use them.



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