[saberdancer]

But there is no reason why it couldn't be done today, even with non-autonomous vehicles. There are cars on the road that can automatically brake if they discover that you are incapacitated, or that something jumped out infront of you. Having some kind of "assisted red light start" which reduces accordion effect could be an easy way of improving throughput. At first only some cars would have it, and effect would be smaller from a system POV, but with time it would propagate.