What happens if you don’t register your car?The pollution is pretty bad in Beijing, but not too much from car waste anymore. I believe sandstorm is a big reason.
The car restriction is also for limiting the traffic. The traffic in Beijing is pretty bad at all times.
On the same topic, it is near impossible to get your car registered in Beijing. Beijing government only wants to issue a very limited new car registrations every so often so you have to enter a lottery to get a car registration privilege. My friend has entered a car registration lottery for 15+ years and she hasn't gotten one.