The Last Mile Versus the Last 1 Percent

The old saw (Pareto) says 80 percent of the cases can be handled with 20 percent of the effort.  An extrapolation would be: self-driving cars can handle 80 percent of the driving very easily but it's the last 5 percent, especially the last 1 percent of the time which is difficult.  Which I find to be rather like the old "last mile" problem in cable: easy enough to move data across country in a flash, but getting it the last mile was difficult. 

Nissan has an answer, whether it's workable remains to be seen.  They're using a telecenter to handle the unexpected problems (like a emergency road crew patching potholes or something).