Beijing will next year ban high-polluting old cars from being driven whenever air quality alerts are issued in the city or neighbouring regions, the city's environmental protection bureau has said.

China has adopted various measures over the years to reduce the blankets of smog, which shroud many of the country's northern cities in the winter, causing hazardous traffic conditions and disrupting daily life.

As of February 15, vehicles which do not meet the Government's current standard on emissions — in practice, those which are more than 10 years old — will be banned in Beijing's main urban area whenever orange or red alerts are issued in Beijing or neighbouring Hebei province and Tianjin city, the bureau said.

Vehicles breaking the restrictions will be fined 100 yuan ($19.73) every four hours they are on the road, it added.

Cars at the National 1 or National 2 emissions standards, which the rules are aimed at, only account for 8 per cent of cars in the city but they account for more than 30 per cent of smog-causing nitrogen oxide emissions, the bureau said.

Vehicles breaking the restrictions will be fined 100 yuan every four hours they are on the road. ( ABC News: Zhang Qian )

The adjustment to regulations also said schools would only be closed selectively during alerts, rather than the blanket approach that was used originally when Beijing issued its first-ever red alert in December last year.

The Government has been tweaking the new system since its introduction, working to unify it across the provinces of Beijing, Tianjin and Hebei.

In February, it raised the minimum threshold for issuing alerts.

Beijing's city Government is also taking measures to reduce the emissions of vehicles driven in the city by using licence plate restrictions to limit the overall number of cars and providing generous subsidies to electric vehicle purchasers to promote fuel-replacement vehicles.

China has adopted various measures over the years to reduce the blankets of smog. ( Reuters: Jason L )

Reuters