Is that a car?  It's definitely a car, it's on a paved flat surface suitable for driving.  Interesting!  Maybe with higher technology they've gotten the noise down to zero and the self-driving can handle the full complexity of surface conditions.  That would save money on underground tunneling, though at cost of valuable surface area, but maybe their urban areas just aren't that dense.

Is that a car?  It's probably a car, it's on a paved flat surface suitable for driving.  Interesting!  Maybe with higher technology they've gotten the noise down to zero and the self-driving can handle the full complexity of surface conditions.  That would save money on underground tunneling, though at cost of valuable surface area, but maybe their urban areas just aren't that dense.