Amazing how all these transportation planners have been saying the same things about diversity for as long as automotivism has been pushing its agenda by means of large government subsidies. One thing the documentary doesn't really concede, however, is that the rail systems do seem to have been quite expensive compared with buses. It's too bad rail engineers and planners couldn't figure out a way to make cheap rail systems considering that they are so much more fuel/energy efficient than vehicles with tires.
As for automatic car plans, I don't think the old plans were as realistic as current ones are today. Someone in the documentary mentions combining GPS with CDROM. He's basically talking about onboard navigation. Who knows how they were planning to implement those long chains of cars that would work in tandem to use highways more efficiently. Maybe with synchronized braking systems?