I believe with the red light cameras, the driver needs to be clearly visible for a ticket to get issued. I would imagine that any such camera-based system would need to be like this. I've heard of a stretch of toll road in FL that you actually go through toll booths and are issued an entry ticket that you give on your way out. If the entry and exit times equate to you speeding, the driver is issued a ticket. That solves the identification problem.