Think about it.
A car that doesn't require you to drive it can come to your house empty and pick you up.
When it drops you off it can pick up somebody else somewhere else.
You'll never have to worry about parking!
With efficiencies of scale kicking in, one of these transportation pods will be makeable for a few thousand dollars.
Goodbye multi-billion dollar street-car and subway infrastructure projects.
The Google-mobile uses surface roads that are already there.
Real-time GPS monitoring will make sure you get where you're going, and a vast network of hardware and software will ensure these "cars" are used as efficiently as possible.
I think they're onto something!