I've thought about this and my own take on it is this is actually an opportunity that has not yet been exploited. The cost of the hardware is $50 now, but that

I've thought about this and my own take on it is this is actually an opportunity that has not yet been exploited. The cost of the hardware is $50 now, but that has only recently become the case. Your reaction might be that it has been $50 for like 5 or 10 years now, and if so my response is that in this area, that is recent. It's a pretty slow-moving, late adopter industry. Most of the equipment getting installed probably hasn't been redesigned in years or decades. The people approving stuff want to buy from known vendors. The vendors are making money steadily now and don't want to go out on a limb with unproven tech. Which doesn't mean it's impossible. I interpret it the opposite way: the fact that it hasn't happened yet doesn't mean it won't or can't. I would expect it to take this long or longer. Also, I think the angle for getting this adopted isn't really efficiency, it's cost saving. Right now, some lights are on sensors (instead of just timing) but they do it with induction loops (https://en.wikipedia.org/wiki/Induction_loop https://en.wikipedia.org/wiki/Induction_loop). If you could match or surpass the reliability of those at a lower cost, you might get people to switch. But once you've crossed that hurdle, you can improve efficiency too, of course. Of course, you have to keep in mind that the camera has to be mounted in the proper position. So it's probably not really $50 of hardware unless you can (in most cases, at least) piggyback on something that already exists. Although that seems possible because the signal light does need to be visible by cars approaching the intersection.