[tempotemporary]

What’s the problem in flashing yellow for a longer period of time? Make a delay long enough for a driver to safely react. Otherwise why bother with flashing yellow anyway?

We have such thing in Ukraine(and probably other ex USSR) countries. There’s no surprise red light. You always know when it’s going to come and have enough time to finish a crossing.

[tsomctl]

It's alleged that cities will reduce the length of the yellow so that people will misjudge and run a red, thus increasing the revenue.

> The annual report for Suffolk County, N.Y., shows that revenue from the red-light cameras was about $28.9 million in 2017, with about $9 million of that paid to the vendor.

[delfinom]

Being in said county, they actually time and report the light timing on the traffic tickets. They actually don't undertime any of the lights from my experience. We really do have bad drivers.

But what happens here is, they pick an intersection, add lights, catch people running it for 2 years, eventually it drops to 0 as everyone gets used it and then proceed to move it to another intersection as the county still pays a minimum invoice to the vendor per month. And once they move it people start running it and the cycle repeats.

The shitty part is the cameras also flagging right hand red turns, you have to basically sit "3 seconds" stopped before doing so by law but it sure as shit better be "double mississipi seconds" or you get a ticket. So people just stop making right on reds at camera intersections and slow down traffic for everyone.¯\_(ツ)_/¯

[HankB99]

The flip side of that is drivers who make a right turn on red w/out stopping - slowing down only enough to maintain control of their vehicle. Some also ignore the signs that stipulate no right turn on red when pedestrians are present, even if there are pedestrians in the crosswalk. I've been nearly run over a couple times in that situation. They're looking for approaching traffic and not where they're going.

As far as simply running red lights, some percentage of drivers - perhaps 1-5% do that at any given intersection. That's often enough that I have to look both ways before proceeding on green to avoid getting hit. That in spite of the 2 second delay between red and green lights. ¯\_(ツ)_/¯

This is in the Chicago suburbs, not sure of other areas. Chicago did have a reputation for shortening the yellow when cameras were installed. I didn't notice that where I live.

[mises]

This is the issue. Yellow light lengths are also inconsistent: I don't know what to expect. Could be long, could be short. It's not always safe to suddenly stop, and we don't know which is which.

[kolinko]

In which country?

Isn’t there some sort of a regulation on the yellow light duration depending on the max allowed speed on the road?

Living in a country with yellow lights, I never had a situation when I could complain that it was too short or too long.

I was taught that yellow means „stop if you can do so comfortably”, and the very few times I ran a red was definitely my bad call.

[tialaramex]

A sensible way for things to work is that traffic engineers interested in safety and flowing traffic work out a rule for how yellow lights work, and that's the rule for the entire country.

Usually your goal is that the yellow lasts long enough that any vehicle which isn't speeding and has brakes at least as good as those required by law, will either pass through the junction while it's still yellow or could easily stop before it goes red. Since even though some drivers will be speeding, anyone who isn't driving a way out-of-specification heap of junk has _much_ better brakes than required by law, this gives plenty of slack. The engineers need to know speed limits on approach roads, the size of the junction (remember, pass _through_ the junction, it's no good if your fast vehicle is still in the middle of the junction when it goes red) and slopes (which affect braking) and various other factors.

However the US is not, on the whole, a country where the sensible way of doing things has much sway. I'd be astonished if there's a Federal Law in the US that sets usable requirements for their whole country, and frankly it wouldn't surprise me if individual towns get to have local politicians just pick a number out of a hat for how long the yellow lasts for the one junction in that town.

[YeahSureWhyNot]

its federally mandated to be between 3 to 6 seconds. towns are free to choose anything in between. some towns that had 5 second yellow lights will change it to 2 seconds after installing a red light camera and make good amount of money from locals who knows the length of the yellow and attempt to blow thru

[kolinko]

So cities change timings in an illegal way? How is this possible :O

[YeahSureWhyNot]

no, typo. they basically change it within limits just to get drivers trapped

[mises]

> In which country?

America.

> Isn't there some soft of a regulation on the yellow light duration depending on the max allowed speed on the road?

Nope.

> Living in a country with yellow lights

Which? It's also possible that you have a local law.

> I was taught that yellow means ,,stop if you can do so comfortably

Unfortunately, red light cameras cause an issue with this. There is time after a yellow for those few times we make the bad call, because it's not always easy to judge in that short of a time. Red lights make this much harder, and may lead us to stop suddenly and unsafely (part-way into the intersection, get rear-ended, etc.).

[kolinko]

Which country - Poland. Just checked, and it’s actually 3s regardless of the speed.

Red light cameras - yeah, also other forms of automatic traffic control. We have some long stretches of roads where the max speed is 120kmph, with traffic lights every few kms + limit 70kmph on the lights + auto speed radar. Which is crazy because you end up watching the speedometer instead of the intersection.

I heard an interesting solution recently - cameras everywhere, but giving drivers a limit of violations they can do without punishment per a given period.

[mises]

Sorry, could you give a little more detail on the solution? I'm not sure I understand. Though I'm certainly wary of "cameras everywhere". Honestly, that's part of what I don't like about red light cameras.

Towns are careful when they want to be. When I'm out on an 80-85 mph highway, they're careful about warning well in advance, putting up signs that a light is coming, etc. But then there are also the small towns which abruptly drop the speed limit from 75 to 55 then to 35 just for their 500 feet of road. And they always have policemen sitting right there and ready to ticket. To your point, these are often areas where you might want to watch traffic (pulling out onto one of these roads is no fun), and this keeps you from doing so.

I think the bottom line is this: traffic laws ought to be designed to keep people safe. Unfortunately, many towns have a conflict of interest with the revenue certain laws bring in. I'm glad that Texas is preventing this. I think it incites officials to set stupidly low yellow light length s (three seconds, apparently the federal minimum by another comment, is rarely enough).

[cher88]

Where I come from our green lights blink five times before the light goes to yellow, then red. I've found that it's much more useful than having just a yellow light to estimate when I should accelerate at a light and when I should stop.

[stjohnswarts]

Nah, Texas did the best thing, take out the useless red light cameras. One less Big Brother operation is always a good thing.

[chrisdhoover]

The best approach is to have all directions go red for a moment. Longer yellows encourage gunning it through the intersection. During the ‘90’s San Francisco had an uptick in pedestrians being run down. The all red idea was touted as a zen pause. Nothing came of it then. 20 years later the City has changed the lights, the lights go all red and the walk light goes on first.

[egorfine]

And this is one of the (many) reasons why people are driving red light in Kiev like it's not even there.