You would have the same issue if you missed the last exit in San Francisco and got stuck going all the way across the Bay Bridge (can easily hit 2 hours trying to go over and back in traffic both ways)
I suspect this is going to be a fundamental issue with AI. Far from some idealized 3 laws of robotics, AIs will need to behave like humans to fit in our society. And that will force us to confront the ways in which we don't follow our own rules - indeed can't follow our own rules, the rules being impractical but a convenient fiction to allow us feel better about ourselves.
I do think there has to be an aggressiveness level in making maneuvers for an autonomous car. It doesn't mean its unsafe, it just means it could be MORE safe if the time penalty isn't big (a decision that regular drivers have a hard time evaluating since we don't measure our own maneuvers' safety accurately)
The solution is to figure out what the traffic rule is based on what the other traffic is doing. But that introduces other pitfalls if you don't do it right.
I guess one benefit of more autonomous vehicles might be cooperation between vehicles to greatly reduce traffic and congestion in these sorts of situations