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Smarter programming of stoplights could improve efficiency of urban traffic

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Re: Smarter programming of stoplights could improve efficiency of urban traffic

#3
post #2

I sometimes get the feeling that traffic signals in my home town (Chicago) are designed to maximize ticket and speed camera revenue, rather than improve the flow.

I don't drive that much these days. When I did, I would occasionally get on the roads very early, when it seemed to me that the Washington, DC, traffic lights were well timed. Once the rush hour started, though, it was not possible to maintain the speeds for which the lights were timed. I suspect that this is the case many other places.

Re: Smarter programming of stoplights could improve efficiency of urban traffic

#4
With all the image processing cameras out there, and the cameras already mounted on the traffic lights, it boggles the mind that nobody is making traffic light controllers that optimize traffic based on current conditions and a cost function.

For example, if 5 cars are coming from one direction, turn the light red for the 1 car on the cross street.

I'm pretty fed up with the light perversely stopping the 5 cars at the last moment to let one car, that is already stopped, enter the intersection from the cross street.

I wonder how much gas and congestion can be saved this way.

Re: Smarter programming of stoplights could improve efficiency of urban traffic

#5
Virginia currently uses smart traffic signals:

> Traffic-responsive signals vary the timing of the lights according to the amount of traffic. They use sensors to detect the number of vehicles on an approach. The time the light stays green adjusts to let as many drivers as possible through before the signal changes to respond to traffic coming from another direction.

Back when I lived in NoVa, the lights near me had this and it was awesome

Re: Smarter programming of stoplights could improve efficiency of urban traffic

#7

With all the image processing cameras out there, and the cameras already mounted on the traffic lights, it boggles the mind that nobody is making traffic light controllers that optimize traffic based on current conditions and a cost function. For example, if 5 cars are coming from one direction, turn the light red for the 1 car on the cross street. I'm pretty fed up with the light perversely stopping the 5 cars at th…

While this sounds great on paper you have to remember that traffic signals are absolutely mission critical components to the traffic system and what you are describing pushes them to the cutting edge of what many might consider "experimental" technology. There can be no trial and error.

Also remember that traffic systems are not developed by start ups that can iterate quickly with seemingly endless funding and/or no overhead. These systems are usually under the control of municipalities that are already strapped for cash and certainly do not have elite teams of developers at their disposal.

Re: Smarter programming of stoplights could improve efficiency of urban traffic

#8
This seems like a nice idea but I actually think it would be terrible. The big discovery recent-ish is "Traffic Expands to Fill Available Road Space" [1]. A situation where traffic lights become smarter to keep traffic balanced between main streets and side streets and between different intersections of the city would just mean result in every single intersection of a given city being in grid-lock simultaneously rather than just some of them.

Already, I've notice that rush-hour lights seem to tuned to take longer than mid-day light - assume that's because any light-change is going to be inefficient (logically enough). But since rush is fated to total congestion anyway, the result just congestion plus tortuously long lights.

[1] http://www.culturechange.org/issue8/traffic%20expands.htm

Re: Smarter programming of stoplights could improve efficiency of urban traffic

#9
post #3
post #2

I sometimes get the feeling that traffic signals in my home town (Chicago) are designed to maximize ticket and speed camera revenue, rather than improve the flow.

I don't drive that much these days. When I did, I would occasionally get on the roads very early, when it seemed to me that the Washington, DC, traffic lights were well timed. Once the rush hour started, though, it was not possible to maintain the speeds for which the lights were timed. I suspect that this is the case many other places.

I wonder if, after a certain density of traffic, these advanced/well timed schemes are actually detrimental?

Re: Smarter programming of stoplights could improve efficiency of urban traffic

#10
post #7

With all the image processing cameras out there, and the cameras already mounted on the traffic lights, it boggles the mind that nobody is making traffic light controllers that optimize traffic based on current conditions and a cost function. For example, if 5 cars are coming from one direction, turn the light red for the 1 car on the cross street. I'm pretty fed up with the light perversely stopping the 5 cars at th…

While this sounds great on paper you have to remember that traffic signals are absolutely mission critical components to the traffic system and what you are describing pushes them to the cutting edge of what many might consider "experimental" technology. There can be no trial and error. Also remember that traffic systems are not developed by start ups that can iterate quickly with seemingly endless funding and/or no…

Sounds like a startup needs to start start developing and licensing traffic light software to municipalities. Seems reasonable enough to me.
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