Sensors on a main road and well set timers after a few months of data can do wonders and be extremely low cost, but it requires some upfront spending and enough public will to put up with bad traffic until everything is tuned.

China has more public transit of every type than the rest of the world combined at this point, and most of their cities are quite pedestrian centric.

Cars are a luxury outside the rural areas, and they’re a problem, but this is unrelated to that.