On Fri, 13 Oct 2017 16:38:38 -0400, Davoud wrote:

Mike Collins:
[Natural gas is] Much better in cities than petrol and diesel.

The best thing for the cities would be to get automobiles out
altogether.

Self-driving electric cars might be a sensible part of a city's
transportation system, though. Especially if they are publicly owned.
That could extend the boundaries within a city where public
transportation would make sense.