Actually what would speed up adoption would be if they were able to drive over the speed limit legally. If they are significantly safer then this should be a win-win for everyone other than those issuing speeding tickets.
People are afraid the cars will follow traffic laws, and drive legally, even when no one else is? And, I find it hard to believe that everyone disobeys the posted speed limits on freeways. For example, trucks with speed-limiters, people who don't want to break the law, buses, etc.