There is steady improvement in the field and roads can be adapted over time, too (special beacons etc.) I feel that the main hurdle to clear will eventually be

There is steady improvement in the field and roads can be adapted over time, too (special beacons etc.) I feel that the main hurdle to clear will eventually be human psyche. We have grown accustomed to the non-zero chance of a fellow human crashing into us, but being flattened by a robot gone wild is deeply repulsive, even if the actual rate of accidents sinks way under the current norm.