If you're in a city that mostly moves people by bus, and has incredibly high construction costs, of course this is the solution they're going to chase. The bus service suffers with more competing vehicles on the road. People prefer rail and dedicated right-of-ways, but they also don't want their neighborhood destroyed while it's built. The transit advocacy groups end up hamstrung by these competing desires.

Uber and Lyft have given everyone a taste of the self-driving car dream (on-demand comfortable private transit) -- they just need to figure out how to get rid of the drivers. It's already producing political pressure to stall or end hugely expensive transit projects because of uncertainty about what a city might really need in 20-30 years.

Hopefully someone's smart enough to show that we'll all still be stuck in the same dumb traffic of our own making, regardless of a human or computer driver, because we really need to be solving for space and land use by minimizing the distance and frequency of vehicle trips instead, public transit included.