foogray

Is it possible you have two separate, unconnected road networks in your city? Did you recently cut off a neighbour connection from your network?

I believe that the no car zots can also be caused by your sims being unable to get to their places of work. Probably something has been left unconnected to your road network. Power plant, possibly? Also, remember that cars can't turn around on avenues unless there's an intersection or roundabout.

Kyushu. The monorail gives it away.

It's definitely Thai but there aren't enough tall buildings to be Bangkok, I think. I'm guessing it's Hatyai.