Truthfully, you cannot escape overcrowding in China. The city where we live has about 1 million people and is considered a "very small city." But look at the photo above, taken while crossing a sky bridge. You see the effects of overcrowding when getting on the bus. People move in mass and push a lot. If it's rush hour don't expect to get a seat. The idiom of being "packed like sardines" is quite appropriate.
Overcrowding does have other problems too. Recently, we read an article about a stampede at a kindergarten. The children were going out to recess when one girl stopped and bent down to tie her shoe. over 40 children were treated for injuries.