"Self Driving" Traffic Lights?

[Alan]

The first traffic light in the world has its 150th anniversary today. I just happened to hear an article on the radio this morning. It was in London at a junction outside of parliament to protect pedestrians after 2 politicians and a traffic policeman had been badly injured. It was manually operated and in line with the railways used red and green lights plus semaphores because gas lights are difficult to see in daylight.

https://londonist.com/london/histor...rst-traffic-lights-in-westminster-looked-like

 

[JoeWras]

IMO...what I think the loops are doing is measuring distance between cars. So 1st car goes, 2nd car right on the tail, 3rd car is a bit back as they are not watching the light..but still make the light. 4th car is watching a you tube video and is back farther still. They are the one that runs the red light. And complains about a short light. Now if all 4 left evenly spaced (not possible but whatever) I think all 4 make it with maybe 1-2 more as well. Utopian science in a perfect world. But also a perfect set up for autonomous cars.

my credentials? I went to college with some Civils. They stayed in a did differential equations. I went out drinking

At least in NC, they have a series of loops. It is pretty basic. Loop 1, means there is at least one car. The second or third loops are spaced back in the lanes and may indicate a stack of a specific number of cars (depends on how far back).

I may be a bad person, but I frequently hang way back in turn lanes with space in front of me in order to activate that last loop. This way, I have a good green arrow and not one that I am tempting fate with. It seems the traffic engineers forgot to add time to green arrows because it takes 5 seconds for the front person to start moving because they are distracted by their phone.

Don't worry about missing Diffy-Q. It sucks. I actually found my diffy-q book last weekend while cleaning, opened it up and laughed. Totally useless drivel.

 

[ERD50]

At least in NC, they have a series of loops. It is pretty basic. Loop 1, means there is at least one car. The second or third loops are spaced back in the lanes and may indicate a stack of a specific number of cars (depends on how far back).

I may be a bad person, but I frequently hang way back in turn lanes with space in front of me in order to activate that last loop. This way, I have a good green arrow and not one that I am tempting fate with. It seems the traffic engineers forgot to add time to green arrows because it takes 5 seconds for the front person to start moving because they are distracted by their phone. ....

Yes, it seems even when they have the inductive loops, the "smarts" are very, very primitive. That's my point, with just a fraction of the sensors and programming that they are putting on these SDCs, an STL could do a lot of smart things to smooth the flow and reduce accidents.

Some of the helpful links provided seem to be pretty old, and not much in the way of updates. Maybe I'm just missing some of the more recent activity, but I'm just surprised this isn't getting more attention. Again, maybe just not 'sexy' enough?

-ERD50

 

[JoeWras]

Yes, it seems even when they have the inductive loops, the "smarts" are very, very primitive. That's my point, with just a fraction of the sensors and programming that they are putting on these SDCs, an STL could do a lot of smart things to smooth the flow and reduce accidents.

Some of the helpful links provided seem to be pretty old, and not much in the way of updates. Maybe I'm just missing some of the more recent activity, but I'm just surprised this isn't getting more attention. Again, maybe just not 'sexy' enough?

-ERD50

My guess is that it is a reliability and maintenance issue. I.E. money. Some of the fancier stuff needs to be monitored for proper operation. The old stuff can go into default mode after taking a lightning strike, etc.

So much more could be done to smarten the infrastructure. The technology is there.

 

[Sunset]

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Or if the SMT saw a car approaching a RED too fast, it could start flashing alarms (audio and visual) and stop the cross traffic.

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It would quickly turn into an easy way to get green lights all the way home, just speed like a demon through the lights... actually encouraging bad driving.

Maybe better would be to pop up a road block to stop the speeding car, better to let the speeding driver smash into a pillar than to smash into other cars or pedestrians. After all the speeder deserves it more than the innocents.

 

[Sunset]

Last summer when in Ottawa, we saw police and ambulance race along a street with stoplights... they had to slow down, sometimes stop and crawl to cross red lights.

Here the lights turn green for the emergency vehicles long before the ambulance gets to the intersection, so all the cars stopped at the red light can go forward and get out of the way.

I was surprised at the lack of advanced traffic control in Ottawa (the Capital of Canada).

 

[ERD50]

It would quickly turn into an easy way to get green lights all the way home, just speed like a demon through the lights... actually encouraging bad driving. ...

Yes, it would probably need to be coupled with a ticketing red light camera, but those seem to get some people (a vocal minority, I think) really worked up.

... Maybe better would be to pop up a road block to stop the speeding car, better to let the speeding driver smash into a pillar than to smash into other cars or pedestrians. After all the speeder deserves it more than the innocents.

I like the way you think!

Hmmm, maybe a paintball gun to mark the offender for later apprehension? And shoot out a bunch of sticky labels, pre-printed with the intersection and a sequence number, so there is no question about it!

-ERD50

 

[gerntz]

We've had many discussions on Self Driving Cars (SDC) over the past few years, and I'm interested in a parallel path - Smart Traffic Lights (SMT).

It just seems that traffic lights with a small subset and expense of the capabilities of the current crop of SDC would be helpful, save lives, injuries, and accident $$$, save time and fuel, and be far easier to implement than SDC. A lot of intersections already have cameras.

A traffic Light does not need to deal with anywhere near the unknowns of an SDC. The layout is known and static. The software would be far simpler, and it seems extremely unlikely to have any dangerous adverse affect (I'm sure present traffic lights have a 'fail safe' mode so that you can't have all GREEN for example).

For example, at busy intersections near us, the most dangerous situation I see is people trying to scramble to get through a short green arrow for a left turn. Safety and traffic would be greatly improved, if that green arrow was intelligent, and matched the time to the number of cars in the left turn lane (up to a limit, but it's silly to let 4 cars go, and stop the 5th - let all 5 go - or be timed for 4 cars, when only 1 is waiting to turn). So the left turners keep going until that yellow light is red, the oncoming traffic hesitates to go even though they have a green, and that frustrates the cars behind them. And then those cars are rushing to get through before they get a yellow. And if the oncoming traffic proceeds, you could have an accident or near miss (and then maybe they get rear-ended).

Or if the SMT saw a car approaching a RED too fast, it could start flashing alarms (audio and visual) and stop the cross traffic.

And just smooth flow to conserve time, gas and brake wear. How many times have you approached a green light, just to have it turn as you got closer, but there was no cross traffic, and no reason for you to stop? And of course, Murphy assures that some cross traffic appears just in time for the light to change and make them stop. What a waste!

And what they learn, and the mass production of these systems might help improve the SDC/assistance tech on cars as well. They can all work together.

The only downside I can see is - will people start playing 'chicken', and just keep going, thinking the light will safely let them proceed? I imagine the camera will catch that, and they can be ticketed. There would be no need for "Right on RED after stopping to yield" (the current complaints of the Red light cameras), if it's safe to go, you will get a GREEN.

What say you?

-ERD50

I say this is prima facie evidence to replace most traffic lights with roundabouts.

 

[ERD50]

I say this is prima facie evidence to replace most traffic lights with roundabouts.

But, but, but... roundabouts are Un-American!

More seriously, I have very little experience with roundabouts. It's clearly a learning curve for people like me. And I think one objection is that they take up a lot of space, which would be an issue at many locations where buildings or other infrastructure already exist.

But they aren't so great on a 55 mph roadway are they (especially if s the majority of traffic is on one road)? Everyone has to slow down to make the curve (and speed up again - brake wear and lost fuel eff%), instead of making some people stop (which would be minimized with a STL algorithm).

-ERD50

 

[gerntz]

But, but, but... roundabouts are Un-American!

More seriously, I have very little experience with roundabouts. It's clearly a learning curve for people like me. And I think one objection is that they take up a lot of space, which would be an issue at many locations where buildings or other infrastructure already exist.

But they aren't so great on a 55 mph roadway are they (especially if s the majority of traffic is on one road)? Everyone has to slow down to make the curve (and speed up again - brake wear and lost fuel eff%), instead of making some people stop (which would be minimized with a STL algorithm).

-ERD50

They only take up a lot of space if you design them that way;i.e., big center circles. In urban areas, England paints ~1 meter diameter white circles on road at intersections & folks know they are rab's. I drove their roads for 6 months in late 90's & thought they were fine.

As for most traffic in one direction, the higher vbolume traffic just goes till there's a gap for the other direction which quickly clears that direction.

Less fuel is lost with rab's imo than with traffic lights. And they don't take the investment of STL's.

Yes, rab's have a learning "curve" - by definition.

 

[ERD50]

... Yes, rab's have a learning "curve" - by definition.

Very good!

... Less fuel is lost with rab's imo than with traffic lights. And they don't take the investment of STL's.
.

A few quick searches and accident reduction with rab does seem impressive, and they claim better average fuel eff% also. But those are compared to traditional traffic controls, so I wonder how they would compare with STL?

Seems the investment in STL would be minimal (we are talking far less tech than what they want to put on a single vehicle), and the street and light configuration are already there.

But I'm often saying we should remain technology agnostic, and focus on solutions, cost/benefit and risk/reward. If rab fit the bill, then we should be using them.

-ERD50

 

[John Galt III]

I think it depends on the jurisdiction. Where I worked they did implement a traffic light control system that purportedly did adjust timing depending on traffic volume and direction (i.e., morning timing was different from evening). From the driver's perspective though, I couldn't see that it made a bit of difference because no matter what the traffic engineers did, traffic volume was simply too high for the existing roadways.

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+1. My neighborhood was great and had very low traffic volume until it was 'discovered' and tens of thousands of people moved here. Now it's like Manhattan here, as far as traffic. And they're still moving in!