This is a really niave take.
Sure they follow rules as well as any other computer but they're gonna be following a set of rules different than the human drivers around them. That's a recipe for a ton of minor accidents.
Hmmm... a "different set of rules than humans" aka following the actual laws that were designed for safety rather than the human rules of "whatever maximizes my personal convenience"
These self-driving cars are going to need to be very careful around people if they operate in cities, but if they are careful enough to be safe, they'll also have to deal with groups of bored teenagers herding the cars around for fun.
Sadly, any rule that can't bend to the fact that people are people is doomed to fail.