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.

Just to add to this:

Current traffic light controllers and/or vehicle detection system (VDS) units are also fairly ruggedised: they're designed to live in outdoor cabinets with minimal active cooling, survive up to +50C (or more) while still operating, and have long replacement lifecycles.

Modern equipment capable of processing imagery "in the field" - some kind of x86 machine - would have a hard time meeting these requirements for the same cost. Ruggedised machines do exist, but at a significant price premium.

The other option would be to ship that data back over fibre (common), but that also creates a dependency issue on the network and may require network hardware upgrades to deal with the big increase in h.264 encoded video traversing the network.

I'd love to see more of this happening, but it's an extremely conservative industry/market.

While traffic lights are mission critical, we can absolutely make it fool proof, the first time. It's actually not very difficult.

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.

Certifying and proving such a system was actually fool proof would be quite costly though, as in house certification would probably not satisfy safety regulations.

Side note: most lights use inductive loops not weight sensors for vehicle detection.

Oh I agree. Building a prototype and proof of concept alone would go along way to getting more on board.

I think the biggest challenge though is getting municipalities to replace current systems. They have already invested millions and millions to get the current traffic system up. It would almost have to be the next cycle of traffic lights, when the old ones get replaced (depreciate fully). And of course, cities would probably want to do their own independent testing/study...

It would be sweet to start seeing them appear on new construction though.

I'm pretty certain there no lights that have "weight" sensors. The sensors for triggering signal changes use large induction loops to detect when ferrous metal (a car frame) is near by.

Yep as I found out with my Carbon road bike, they don't see me (or a bunch of us) which can be fun.

A strong neodymium magnet attached to your shoe or one of your components should be enough to trigger the sensor for the lights, I've seen them work on scooters and small motorcycles.

This is an excellent idea, thanks!

Currently off my bike due to ill health but will suggest it to the cycling club.

No worries! Some people suggest using a stainless metal case around the magnet since they tend to oxidize a bit, but there are a few good guides around with ideas.

I agree with you that the cameras could be made fool proof, or close enough with a fall back at least that it would still be beneficial. I just wanted to point out that the vast majority of car sensors use an inductive loop which is far less prone to damage and relatively inexpensive compared to weight sensors.

Think I remember reading that the failsafes in traffic signals are hard-wired. e.g. the green light in one direction is grounded through the green light in the crossing direction, so they can't both be illuminated at the same time. The idea is that no matter what goes wrong with the control software or sensors, you can't get conflicting green lights.

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

That's not a terrible idea but once again you run into the issues of reliability and budget. At the end of the day you need to convince city officials to spend what little money they have remaining in their budget on your new system because it offers a greater value than all of their other proposed upgrades to the city AND that what you have is as reliable or better than the current system they have in place. This means asking them to trust a small company they've never heard of to manage the transit systems for their city and potentially drop contracts with companies that they have been working with for a very long time (remember this is politics). Also keep in mind that software or hardware failure in these systems could result in multiple fatalities. I'm not trying to be a naysayer, it's just important to recognize that getting something like this implemented is not as easy as convincing consumers to try/buy your product.

The best bet would probably be to get a forward-thinking city to experiment with this in a small area and then go from there.

The city already has no problem funding cameras mounted on every traffic light, and all kinds of other surveillance equipment. A generic, self-adapting light controller would work for probably 90% of intersections. I'm hard pressed to see how it would be that expensive.

It would not be hard to put in a physical interlock so both lights could not be simultaneously green, regardless of what the software commands. I don't believe this is a significant fatality risk.

I would assume mounting cameras on traffic lights is an easier sell to a city, since they can be marketed as a revenue generation device.

This sort of local development work sounds like a project for Bill Gates.

Had a friend who worked in Energy Efficiency for a U.S. state. It was a real struggle for them to get people to switch traffic lights over to LEDs from incandescents, even though the LEDs were superior - lot of risk-aversion.

I would like to see this as a temporary fix for when a signal goes down... toss a bolas with a camera + light that wraps around the cross-bar and can temporarily handle things. (Good luck getting it down!)

This exists in plenty of places. See the comment below yours.