In cases of very high pollution, cities such as Beijing or Delhi have introduced 'odd and even numberplate' traffic regulations. For example on the 8th December 2015 in Beijing.
The schemes can have an impact on traffic and pollution in the short term in extreme situations - but at the cost of significant inconvienience. If they become longer term measures, then their impact reduces.
In Europe, more sustainable, longer term measures, such as low emission zones , congestion charging and traffic limited zones are very effectively used. For more details on the impact of odd and even schemes, see our FAQ on odd-even schemes.