An official in Shijiazhuang said it is still uncertain whether the city, one of the most polluted in China, will introduce traffic restrictions based on cars' license plates.

There are plans for the capital of Hebei province to introduce an "odd-even" policy that restricts car use in the city on alternate days, depending on whether their license plates end in odd or even numbers.

For a two-month period around the 2008 Olympic Games, Beijing reduced emissions by using the system.

Should the plan take effect as scheduled next year, each private car will only be allowed on the road three or four days a week.

Shijiazhuang also plans to restrict the number of cars available for purchase starting from 2015.

Yang Weifeng, an official from the information office of the city government, did not confirm the statement with China Daily on Wednesday.

"It is simply one of the many suggestions to combat airborne pollution in the city in the next five years raised by the Shijiazhuang government, but the media took this one and made a fuss about it," he said.

"Right now it is still a guidance or a plan. The processes of conducting scientific appraisals and making a concrete roadmap haven't started yet."

Yang said other processes, such as public hearings, are also required before its implementation.

The Ministry of Environmental Protection released the May air-quality figures of 74 key cities on Wednesday. Shijiazhuang was among the top 10 most polluted cities.

Airborne pollution caused by exhaust emissions accounted for about 22 percent of the smog and haze that shrouded a large area of the country in January, below only the contribution of coal-fired power-stations.

The Shijiazhuang government has vowed to bring the number of motor vehicles in the city to less than 1.9 million by the end of 2013, and 2.3 million by the end of 2017.

"I think (the even-odd plan) is a good measure, which can not only relieve the pollution, but also ease the bad traffic in the city," said Lei Tian, 27, who came back to Shijiazhuang from Birmingham in the UK in September.

"The air quality is just so bad in my hometown," she said. "My throat suddenly felt very uncomfortable after I came out of the plane and shouted 'Hooray' when I came back from England."

She also complained about the traffic jam that takes her sister more than an hour to get to work in the morning, longer than the average commute in Beijing, which is about 50 minutes. The urban area in Shijiazhuang is only about a third the size of the urban area in Beijing.

But some questioned the feasibility of the policy, worrying that rashly implementing it may provoke resistance from the public.

"Cars in Beijing are forbidden on the roads for only one day a week. The Shijiazhuang government is pushing this policy so hastily," said Zhang Yanchen, 27, who has his own car but only uses it on weekends.

He worries that public buses may become much more crowded in the future, and said that coal-fired power stations are still the biggest polluters in the city.

Ten measures to curb air pollution that are plaguing the country were outlined on Friday during an executive meeting of the State Council, presided over by Premier Li Keqiang, including restricting traffic flow during periods of heavy pollution.

Contact the writers at wuwencong@chinadaily.com.cn and zhengjinran@chinadaily.com.cn