This is sort of the thing though - people can experiment and test the limits of a driverless system with little to no consequences. Once they know those limits,

This is sort of the thing though - people can experiment and test the limits of a driverless system with little to no consequences. Once they know those limits, they can abuse them, knowing when it's always safe to cut off a driverless car for example. I can picturing all the videos on youtube now about how to fuck with these things. With human drivers, that unpredictability factor adds to a level of fear which often prevents this sort of behavior. I think there's also a primed number of people who would do this out of open hostility to self-driving cars, "took our jobs" types, etc and a lot of people who would do it just for fun or to make their own trips quicker.