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…
Don't forget, many lights right now are using weight sensors in the ground (SEE EDIT-2), A. that is very costly, B. They are prone to damage...a lot of the time, and C. with current technology in cameras, I'd say they will be more reliable and give better information about on-coming cars from all directions to the traffic light.
It is quite simple to say, if the conditions are bad for visibility, or the camera is inoperable, or even a bird is sitting in front of it, whatever it is, the simple fall back can be 'dumb'. A timer. As they have been for many many years.
I've thought about this a lot and imagine in the future that each intersection will actually be able to communicate with the on board systems of autonomous vehicles and create a very efficient system. At that point, many intersections would not even require vehicles to stop. It would regulate the speed of each vehicle so each one could go through with minimal energy impact. ...Sure...it might be a 'close your eyes' moment...but regardless, we can make it safer than how it is today...with humans making the stop/go decisions.
Whatever upgraded systems in traffic lights we move to, we have to start thinking about autonomous driving. It will be a HUGE leap forward in not only getting around efficiently, but getting around quicker! Human driving tendencies are inherently inefficient. The slinky effect on roads and highways is quite annoying.
EDIT: Another 'efficient' thing we can do is place short range charges into the ground near the stopping point at lights. This is down the road when a majority of cars on the road are fully electric. But as the vehicles sits at a light, it would charge. The power would be obtained through using photocells on the surface, so when a car is not currently waiting on top of it, they are building a charge. This of course would require the price of batteries to go way down to be feasible, but essentially, all forms of consumer transportation will be powered by solar.
EDIT-2: I'm wrong about weight sensors, I actually did not know about inductive loops at lights. TIL. Either way, they have a limited range of detection.