I don't think that's true at all. There was an article posted about the subject a while ago, but the thrust of it was that researchers think they need to do more to make cars behave like (fully attentive) human drivers rather than being weird anomalies that behave in surprising/irritating (to humans) ways if they're going to actually go on the road, and I think that's completely right.
"(fully attentive) human drivers" probably cause deadly accidents every day, and they certainly behave in surprising/irritating ways. Anyways, a human driver going the speed limit is no hazard, so I fail to see how having self-driving cars follow the limits could be a problem.
