From what I understand, Chinese people see bicycle riding as a sign of poverty, so everyone in China buys a car if they're at all able to afford one and uses it as much as possible even if it's silly to do so. Take that in the country with a huge population highly concentrated in a few small areas, add in the fact that Chinese built cars have basically no pollution controls and you get the conditions that you see in Chinese cities these days, where there's so much pollution that you can't see across the street some days and there are estimates that it's taking 5 to 10 years off the lifespan of residents.