i don't understand why nobody sees them as a symbiosis. We haven't solved anything if driverless cars are clogging up the highway, but they can solve one of the biggest problems for mass transit, the last/first kilometres. I don't know anything specific about the bullet train, but most of the time the problem is getting to/from the bullet-train. If it shortens your travel by one hour, but you have to wait 2 hours for a bus to get to the station it's not going to work.