Traffic light loops

[timtofly]

If there is a short yellow, my wife accelerates, if it is a long yellow, she slams on the brakes.

The Germans are very engineering minded. A "double" yellow, just means they have to think about what to do next instead of driving around mindlesly.

If every one accelerated on a yellow though, yellow would remind those stopped to wait for all the accelerating vehicles to leave the area. Normally if one was stopped, they should make sure the traffic cleared before moving again any ways.


What gets me, is the flashing red light. If it is clear and I have to wait to stop, by the time I get started again the traffic is in my way. I just go because it is clear. The worse thing that you want in traffic is for people to hesitate and disrupt the flow.

 

[LucyDuke]

I've driven around nova so much that I know when the traffic lights switch from red to green. They also go in the same order.

That's typical outside of actively managed areas.

I usually watch the signals facing other directions, waiting for the yellow on the green before mine. Yellow for you only means accelerate when it's fresh and you know it's long.

 

[History_Buff]

Here the lights to Red --> Green --> Yellow --> Red --> Green, no overlap.

I've driven in Switzerland, and would much prefer their system of Red --> Red & Yellow --> Green --> Yellow --> Red. Stops me from having to watch the opposing signals and guessing as to when I go.

 

[ZeletDude]

Red to Green, To Yellow, To Red again

 

[Old Hippy]

Edit: Actually, I believe that flashing yellow lights do mean that cars must stop before entering the intersection. I think flashing lights typically indicate a malfunction in the system that controls traffic timing.

not sure if they still do it here in Australia, but the lights used to flash amber late at night in the CBD, (1am to about 5am) it just meant use caution and proceed ...
haven't seen it lately but i drive through the CBD less nowdays at that time of night

 

[Formaldehyde]

Here the lights to Red --> Green --> Yellow --> Red --> Green, no overlap.

I've driven in Switzerland, and would much prefer their system of Red --> Red & Yellow --> Green --> Yellow --> Red. Stops me from having to watch the opposing signals and guessing as to when I go.

The signals here are almost always hooded so you cannot see them from the side, even at night. They specifically do not want you to be able to know when the light is going to turn, even though it is usually obvious if you watch the traffic.

I should watch the traffic coming from the side even more closely than I do after the light turns green. It is all too easy to be killed by someone not paying attention to the traffic lights.

 

[LegionSteve]

Yellow is also stop.
...
A yellow or amber signal light means that you must stop before entering the intersection, if you can stop safely.

It is the same in the UK highway code. It does NOT mean accelerate and try to get through before it changes to red, although that is what happens in practice.

The UK system of going red -> red+amber -> green is quite useful for me, because my car has that automatic stop/start thing to save fuel. So for me, red+amber means "depress clutch pedal to start engine."

 

[say1988]

Yellow does not mean slow or stop, it means caution. When you see a yellow light you must quickly decide whether you can make it into the intersection before it changes to red. If you cannot, then you must stop. If you can, then you ought to speed up.

Technically it is the opposite. If it is possible to do do so safely, you are supposed to stop even if you can safely get through the intersection. You are only supposed to go through if you are already committed. Its just not really enforced anywhere I have ever been, though.

Those wishing to turn left typically drive halfway into the intersection before the light turns red to wait until it is safe to turn. This means that legal left turns frequently take place during that 2 second window when there are red lights in all directions.

That is what people do, and is generally accepted, but technically that should not happen. You should not enter the intersection if you cannot get through it under the green light (or yellow if you commit under a green).

 

[Trev]

Where there is no turning arrow, 1 car only is allowed to enter the interesection and wait for space in oncoming traffic to complete the turn in Australia, often however several cars will do that. Amber does not mean accerelate in Australia because many intersections have associated speed cameras that will take your picture if you do that, also take your picture if light has changed to red. So if you visit and drive in Australia, caution on yellow means accelerate is recommended.

 

[Silurian]

The signals here are almost always hooded so you cannot see them from the side, even at night. They specifically do not want you to be able to know when the light is going to turn, even though it is usually obvious if you watch the traffic.

I should watch the traffic coming from the side even more closely than I do after the light turns green. It is all too easy to be killed by someone not paying attention to the traffic lights.

In the US the roads are wider (generally) and so can get more cars through the junction per hour when green. In the UK a 3050 wide approach will allow 1850 cars through and a 5200 wide approach will allow 2700 cars an hour if green all the time.

At a small traffic controlled cross roads you could have on North South Red from 0 to 2 seconds then Red Amber 2 to 4 second then Green. On East West Green to 0 then Amber 0 to 3 seconds then Red. So there is 4 seconds intergreen time when the junction is not being used. On larger junctions, less sight or with faster moving traffic the intergreen time is increased by adding in all red portion.

As Gin and tonic pointed out it takes people time to react and if they did not receive a warning of the start of the green time the first second of the traffic phase would be wasted. If you have a number of wide lanes with little traffic in each that is not so important but if you have one narrow lane it does.

I studied traffic light design at collage but have never designed a layout for real. I have manually controlled traffic lights during the rush hour which gave me a certain sense of power.

 

[Formaldehyde]

It is the same in the UK highway code. It does NOT mean accelerate and try to get through before it changes to red, although that is what happens in practice.

It is actually illegal in most states to accelerate to get into the intersection before the light turns red.

As Gin and tonic pointed out it takes people time to react and if they did not receive a warning of the start of the green time the first second of the traffic phase would be wasted. If you have a number of wide lanes with little traffic in each that is not so important but if you have one narrow lane it does.

It wasn't always that way. It used to be that you were given advanced notice that the light would turn green and the other light went green the exact moment the other went red. But they found that by hooding the traffic signals and creating a delay between the changes that it would substantially reduce the number of traffic accidents. It makes the intersections less efficient but safer.

Traffic in the US has become so regulated that it is becoming extremely rare to even be given the opportunity to decide when to turn left across multiple lanes of traffic. This is especially true at intersections. It used to drive me nuts in the SF Bay area to have to wait for a left turn signal at night or on the weekends when there was no traffic at all.

The problem is that the vast majority of people simply don't pay sufficient attention when they drive in the US. So the state is forced into taking many of the decisions out of their hands while reducing the speed limits to absurd levels in areas where you should be able to drive much faster.

 

[Silurian]

It is actually illegal in most states to accelerate to get into the intersection before the light turns red.

In the UK you could be charged with "driving without due care and attention" for this.

It wasn't always that way. It used to be that you were given advanced notice that the light would turn green and the other light went green the exact moment the other went red. But they found that by hooding the traffic signals and creating a delay between the changes that it would substantially reduce the number of traffic accidents. It makes the intersections less efficient but safer.

Well in the example I gave above there is 4 seconds intergreen time which was the minimumin in the UK (I do not know what it is now). So in the UK you will be warned that your light will turn green at least 2 seconds after the other light(s) have turned red. Never heard of swaping greens with no delay.

 

[Formaldehyde]

Well, that actually makes good sense. I hate it when the person ahead isn't paying any attention which causes a few, or even nobody, to be able to make the turn.

And to be fair, I don't think the traffic signals on highways where the speeds are above 45 mph have ever instantaneously changed. But it was frequently done at lower speeds and still is. it is one of the reasons why red light cameras have come into vogue. it is now a major source of revenue in some municipalities.

Many of the traffic laws and control measures in the US are directly related to most people simply not paying enough attention while driving 4000 lb projectiles.

 

[NickyJ]

Here it is red -> green -> yellow -> red

There is no warning that a red light is about to turn green, except for seeing that card from other directions are stopping. A red light in one direction will not turn green until 2 seconds after the light in the other direction has turned red.

As a Virginian, this. (I don't know if it's different state-by-state, or whatever.)

 

[Antilogic]

As a Virginian, this. (I don't know if it's different state-by-state, or whatever.)

I think the red -> green -> yellow -> red cycle is universal in the United States. It's the only system I've driven with, so it's hard to really evaluate my preferences for the poll.

 

[History_Buff]

The signals here are almost always hooded so you cannot see them from the side, even at night. They specifically do not want you to be able to know when the light is going to turn, even though it is usually obvious if you watch the traffic.

I should watch the traffic coming from the side even more closely than I do after the light turns green. It is all too easy to be killed by someone not paying attention to the traffic lights.

Well I'm certainly not trying to advocate that we all blindly accelerate into greens, but it's still better to have an pre-green yellow. Imagine I'm stopped with a red right facing me, because the traffic coming the opposite direction has an advanced green turning signal going. But if there's nobody coming that way, I can't guess when their right goes red, and thus when mine will go green.

And in rush hour traffic, we owe a duty to our fellow commuters to be in gear and ready to go the moment that light turns.

I think the red -> green -> yellow -> red cycle is universal in the United States. It's the only system I've driven with, so it's hard to really evaluate my preferences for the poll.

I think it's all of North America, and likely the Americas as a whole.

 

[Zelig]

And in rush hour traffic, we owe a duty to our fellow commuters to be in gear and ready to go the moment that light turns.

Well, as long as everyone is consistent, it doesn't really matter how fast they are, you can adjust light timing as necessary.

 

[Formaldehyde]

And in rush hour traffic, we owe a duty to our fellow commuters to be in gear and ready to go the moment that light turns.

It's really not all that difficult. All one must do is pay a bit of attention and accelerate when the light turns green.

 

[Jan H]

Except in, apparently, the Netherlands and Belgium?

No, the Netherlands and Belgium are Red -> Green -> Yellow -> Red, like most countries. I think the OP made a mistake in his poll.

Only we call the "yellow" light "orange" . For the rest, the rules are the same as anywhere: legaly, "yellow" means that you have to stop (just as on red), unless you are unable to safely do so. In practice this means that a lot of people just ignore the yellow, or accelerate to make it to the intersection before the red...

I actually like the German/British system, where the green light is announced by a short combination of red and yellow. Another thing I have seen abroad (somewhere in Asia, don't remember where exactly): a number below the trafficlight that counts back from 9 to 0 before the light changes from red to green. It almost felt like the start of a F1 race...

 

[Bugfatty300]

I just ignore stop lights and signs altogether. Most of the time it isn't a problem.