They're far enough away that it doesn't make sense to put off purchasing normal buses (which could probably be retrofitted with self-driving tech anyway). And

They're far enough away that it doesn't make sense to put off purchasing normal buses (which could probably be retrofitted with self-driving tech anyway). And certainly that doesn't obviate the value of things like planning and beginning to carry people on routes; setting up stops (signs or shelters); and setting up bus lanes. And rail transit is a whole other beast. Do you know how much higher a volume of people can be carried by a subway than by even the most efficient bus route running buses bumper-to-bumper (let alone private vehicles)? (The unwillingness of politicians to acknowledge this is one of the reasons the L train shutdown in Brooklyn next year is going to be such a shit show.)