I think so, at some point, in the same sense that I can't take a bicycle onto a highway or that I can't take a horse on most streets. I know it's kind of a silly example, but it is the case that there was a 40-year period in which horses and cars were mixed. I'm expecting about a 30-year or 40-year period in which driven vehicles and driverless vehicles will be sharing roadways in some way. They may be somewhat grade separated, but there is no way we can afford grade separation everywhere, so there is going to be mixed traffic at some point.
On March 28th, 2018. See this statement in context.