In the medium term, I expect self driving cars will instead start to communicate with each other to find a better approximation of optional traffic flow (by finding the solution that is best for the negotiating vehicles). This has several competitive advantages over the simple algorithm: it enhances safety for participating vehicles by removing prediction errors, and if you can negotiate with the other car instead of guessing what it will do you can do much tighter manoeuvers with smaller seaters margins. And of course better traffic flow makes driving more pleasant, which is good for car sales. Given all those market forces I think it's very likely to happen.