In my experience, the cars in the slow lane are often going well below the speed limit. So you could easily have self-driving cars, driving at the speed limit,

In my experience, the cars in the slow lane are often going well below the speed limit. So you could easily have self-driving cars, driving at the speed limit, in the passing lane. I'm curious if they would be programmed to 'move in' to allow a faster (exceeding speed limit) car to pass.