It'd be interesting to see how this compares in overall efficiency to properly implemented and comprehensive mass transit systems in a dense urban environment. The Tokyo metro alone (not including the JR trains, Tokyo Subway—a separate but compatible subway system, and other train transit systems which totals over 40 million daily users) handles 6.8 million passengers daily just in one city . https://en.wikipedia.org…
This is maybe true in exceptional cities like NYC and Tokyo, but for the vast majority of US cities the fraction of cars on the road that are taxis is negligible. Autonomous service will almost certainly increase the average number of passengers per vehicle, thereby greatly improving the efficiency of the road system. (Obviously a better/cheaper system can induce demand, increasing overall congestion, but this is the case with all improvements to transportation and simply signals that more value is being delivered.) Yes, small cars will have difficulty matching the passenger volume of trains, but autonomous vans and buses will come much closer and with vastly more flexibility than trains.