Smart Traffic Lights

[pete c]

Not sure where this thread belongs, so I guess this is as good a place as any.

Why aren't they at every intersection yet?

I am not talking about the M.A.D. (magnetic annomaly detectors) imbedded in pavement at intersections. Those have been around forever. Trouble is, they require you to stop and they have no way of keeping a light green long enough for approaching traffic.

I googled it and there is some work being done with things like light networks that are tied together and lights that communicate with cell phones, but both of these are complex. I would like to see a simpledevice that used cameras mounted on lights that looked down the various approaches and using image recognition software would turn a light green as traffic approached. It could also hold a light green if traffic was near.

The benefits besides fuel savings would be safety as you would no longer accelerate to try to beat a yellow, if the light saw you coming and held green a few seconds more. You could also program them to recognize when someone was approaching at a speed well above the limit and turn red. Once speeders realized what was happening, it would affect their behavior around intersections.

It seems to me that this is a no brainer. It would save huge amounts of fuel, peoples time, brake pads and lives. Government mandates all sorts of silly **** that results in miniscule savings of fuel/emissions. Why doesn't it push this technology.

It would also eliminate the expensive process of tearing up pavement and running all sorts of cabling to do the job, very poorly.

[Xist]

Supposedly, our major intersections are timed, so that if you drive the speed limit, you do not hit red lights, but that has not been my experience.

However, minor intersections seemed timed to make me stop, although I wonder if that is avoidable.

[pete c]

It really pisses me off when you are driving along a deserted road and you come up to an intersection and the light goes red just before you get there. You then sit through a red light and of course there is no traffic coming the other way. There really is no excuse for this huge waste of time and fuel.

As for lights being timed, I have heard that but rarely experienced it. Also, how could the lights be timed for both directions?

[redpoint5]

Another benefit of smart lights is that they could detect a vehicle that is failing to stop at their red, and hold the cross traffic with a red light to avoid the collision. People should be responsible for checking both ways before entering an intersection, but apparently they don't as they still get hit by red light runners.

[The Other Andy]

Roundabouts. Problem solved.

[Xist]

Cloverleaf interchanges?

[gone-ot]

Originally Posted by The Other Andy

Roundabouts. Problem solved.

Roundabouts = tangent velocity circles!

[darcane]

Originally Posted by pete c

It really pisses me off when you are driving along a deserted road and you come up to an intersection and the light goes red just before you get there. You then sit through a red light and of course there is no traffic coming the other way. There really is no excuse for this huge waste of time and fuel.

As for lights being timed, I have heard that but rarely experienced it. Also, how could the lights be timed for both directions?

Anchorage, Alaska has (had?) timed lights on the major routes through the city. The timing changed during the day based on typical traffic flows. It's fantastic and a little surreal having every light turn green as you approach the intersections.

I thought it worked really well and it's one thing I miss now that I've moved south.

[freebeard]

I think the Germans call it 'surfing the green wave'. My son pointed out once in Seattle that the green wave was rolling backwards.

The system you suggest exists for fire engines. They can force a green light; otherwise the cross-town traffic has to be interleaved.

I googled it and there is some work being done with things like light networks that are tied together and lights that communicate with cell phones, but both of these are complex.

[Citation needed] Was it EnLighten?

It would also eliminate the expensive process of tearing up pavement and running all sorts of cabling to do the job, very poorly.

All EnLighten requires is a backend intertie between the municipal servers and a smartphone app. What you propose requires replacing infrastructure.

Time to petition your city government.

[UFO]

Originally Posted by pete c

It seems to me that this is a no brainer. It would save huge amounts of fuel, peoples time, brake pads and lives. Government mandates all sorts of silly **** that results in miniscule savings of fuel/emissions. Why doesn't it push this technology.

To us subject to fuel prices and traffic interruptions, you are correct, this is a no-brainer. But to assume this is the goal of cities and traffic engineers is a mistake.

Sometimes stopping the flow of traffic is the goal, such as the new lights installed at a recently opened Mal-Wart near me. These lights are timed against the normal flow, and even have no proximity sensors so traffic is forced to stop even if no one is entering or leaving the store parking. Why? My guess is to simply make people aware of the store, and make it easy to stop/shop there.

There are numerous thoroughfares in Denver that seem to encourage speeding, as one must drive at least 15mph over the posted limit to ensure green lights. Not all are like this, Speer Blvd and Broadway both seem appropriately timed on the sections I regularly drive. But I like the idea of traffic monitoring and triggering lights in advance of traffic, it would save huge amounts of fuel given the typical oblivious drivers rushing up to red lights and slowing for lights about to turn.