Went to London and had a ride on these at Heathrow (not my photo, camera was still in my case)

It's kind of like Minority Report meets a London taxi.

I could really see these catching on. Imagine them instead of New York subway trains. You wouldn't have to stop at every station, just go the fastest route to where you need to go. Shame they'd get fucked up and filled with rats and piss though.