A traffic light would only need to solve a much simpler problem than an autonomous car- after image-recognition, given the number of cars waiting/approaching at

A traffic light would only need to solve a much simpler problem than an autonomous car- after image-recognition, given the number of cars waiting/approaching at each direction, decide which lane(s) to give a green light to. Finding a reasonably optimal policy could be hard, yes, but once one is found that could be applied to all (or most) traffic lights, and it couldn't plausibly be more computationally intensive to run than the image-recognition step. Meanwhile, if conversation involves a plausible future where all/most vehicles (inevitably including police cars and other government-owned vehicles) are autonomous and have the same kind of sensors, its hard to imagine the anti-surveillance angle being a decisive factor. I'm not for pervasive surveillance, and perhaps the NSA will be nice and claim really convincingly that they can't access records from traffic lights... but that bird has flown, anyway.