Automotive

Strange traffic light behavior

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  • Jan 5th, 2023 3:03 pm
[OP]
Jr. Member
May 20, 2008
145 posts
194 upvotes
Toronto

Strange traffic light behavior

I was always intrigued by non-intuitive traffic light programming.
On on-demand intersections lights turn green only when a vehicle approaches or a pedestrian pushed a button. Of course some programming has to prevent light sticking. That's where Canada (only Ontario?) and other countries differ. In other countries they run a counter from the last light change and prevent it from changing again within a certain period of time. Here in Ontario they run a counter from the moment the button was pushed or vehicle arrived. The result is very strange: when the road is empty every car or pedestrian has to wait for no apparent reason.

Is this an act of pure stupidity or there is a good reason for this strange behavior?
11 replies
Deal Guru
Oct 6, 2007
10119 posts
8153 upvotes
Kootenays
The logic for it, by my reasoning, is if the main road is usually the one with the green light, particularly on a road with a speed limit above 50 kph, if the green light went amber, then red as soon as the cross traffic approached, then the main road traffic approaching would not have time to slow down before the light change. We have an intersection like this close to me. The main road is 70 kph. I've learned that if I'm approaching that intersection and I see a vehicle coming on either side of the cross road, I'd better get ready for a quick stop, because as soon as the other car comes to a stop, the amber comes on, followed by the red. I would much prefer that the cross traffic had to wait a few seconds.
Sr. Member
Jan 29, 2014
549 posts
608 upvotes
Toronto
It's always annoying at those intersections where the countdown goes to zero but the light doesn't turn yellow. Instead the white "walk" signal turns back on and the light remains green. It's like the traffic light saying "SIKE!"
Member
Nov 20, 2014
300 posts
103 upvotes
Ottawa, ON
professormeth wrote: It's always annoying at those intersections where the countdown goes to zero but the light doesn't turn yellow. Instead the white "walk" signal turns back on and the light remains green. It's like the traffic light saying "SIKE!"
The worst thing is the drivers that begin braking when the countdown is close to zero! Then it turns white and they look like even bigger clowns than usual.
[OP]
Jr. Member
May 20, 2008
145 posts
194 upvotes
Toronto
I did a quick calculation, correct if my assumptions are off. There are about 3.5 thousand of traffic lights in Toronto. Major road intersections do not listen to pedestrian and car demands, so exclude about a third. Assume there are 10 vehicles or pedestrian cross vacant intersection per day and it takes 2 minutes of wait before they are allowed to cross.

The result is 250 thousand hours of idling per year only in Toronto! Ouch!
Deal Addict
Oct 1, 2015
2761 posts
3834 upvotes
Barrie, ON
SizableSac wrote: The worst thing is the drivers that begin braking when the countdown is close to zero! Then it turns white and they look like even bigger clowns than usual.
Idiots, lol.
Deal Addict
Sep 14, 2012
1501 posts
2153 upvotes
Toronto
professormeth wrote: It's always annoying at those intersections where the countdown goes to zero but the light doesn't turn yellow. Instead the white "walk" signal turns back on and the light remains green. It's like the traffic light saying "SIKE!"
That would in fact be Psych, not Sike.
Deal Expert
User avatar
Jan 27, 2004
50577 posts
14946 upvotes
ONTARIO
professormeth wrote: It's always annoying at those intersections where the countdown goes to zero but the light doesn't turn yellow. Instead the white "walk" signal turns back on and the light remains green. It's like the traffic light saying "SIKE!"
Exactly. So true! They say drivers should ignore the count down timer. Those are for pedestrians. Which is true.
But when you have something GLOWING that shade of super hyper visible yellow saying "5! 4! 3! 2! 1!" It just grabs your attention and makes you want to react to it.
Sr. Member
User avatar
Aug 6, 2017
897 posts
1558 upvotes
SizableSac wrote: The worst thing is the drivers that begin braking when the countdown is close to zero! Then it turns white and they look like even bigger clowns than usual.
I see that happen when there is a red light camera at that particular intersection. Quite understandable as the city keeps adding more and more of these things.
Deal Addict
Jan 12, 2017
1661 posts
975 upvotes
Without a doubt, there is an insane amount of wasted idle time and many of the design are outright incorrect.

However, the approach you've noted are just two options that both work (given the maturity of current traffic control) - in 'other countries', this creates larger blocks of time for pedestrians to aggregate and cross together more efficiently. In most of Canada, outside of Toronto, pedestrian volumes generally aren't sufficient for this.

Some corridors in Toronto have semi-coordinated traffic signals, but generally, this is a huge area of inefficiency. Some places have built roundabouts as a way to improve this major traffic constraint, but that take a lot of space that isn't feasible in most locations. When there is a need for serious capacity, you see major construction of controlled access (ramps) highways that do away with all signals.

I would say there is a reason for the behaviour, but not one we should be content with, and has huge improvement potential.
Karlik wrote: I was always intrigued by non-intuitive traffic light programming.
On on-demand intersections lights turn green only when a vehicle approaches or a pedestrian pushed a button. Of course some programming has to prevent light sticking. That's where Canada (only Ontario?) and other countries differ. In other countries they run a counter from the last light change and prevent it from changing again within a certain period of time. Here in Ontario they run a counter from the moment the button was pushed or vehicle arrived. The result is very strange: when the road is empty every car or pedestrian has to wait for no apparent reason.

Is this an act of pure stupidity or there is a good reason for this strange behavior?
Deal Guru
User avatar
Nov 27, 2005
12349 posts
2528 upvotes
Richmond Hill
UrbanPoet wrote: Exactly. So true! They say drivers should ignore the count down timer. Those are for pedestrians. Which is true.
But when you have something GLOWING that shade of super hyper visible yellow saying "5! 4! 3! 2! 1!" It just grabs your attention and makes you want to react to it.
Yup, this is a case of excessive information given to drivers. Regardless of whether drivers should be looking at the pedestrian signals or not, the fact of the matter is that it's highly visible and impossible to ignore.
Deal Fanatic
Jul 26, 2007
6792 posts
4361 upvotes
Toronto
professormeth wrote: It's always annoying at those intersections where the countdown goes to zero but the light doesn't turn yellow. Instead the white "walk" signal turns back on and the light remains green. It's like the traffic light saying "SIKE!"
Countdown is for speeding up.

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