Experts, locals question the city's proposal to restrict cars, Li Fusheng reports.

Beijing is eyeing legislation to limit the number of vehicles on streets to ease traffic jams and curb air pollution.

The city government has limited the use of cars on streets and highways six times since 2008 as an emergency measure, but it has never written the limitations into law.

There has been recent public criticism that enactment of legislation this year could pave the way for permanent restrictions.

The legislation proposal was among 10 presented to the Beijing Municipal People's Congress in late January.

Li Xiaojuan, a city official, said the proposal would ban the use of cars based on the last digit of license plates on alternate days.

Li said legislation will be formally announced this year if the proposal is passed at the people's congress.

Beijing Mayor Wang Anshun likened the proposal to choosing between the lesser of two evils.

"When there is severe air pollution, what is more important, the right to drive a car or our health?" said Wang during a January session of the municipal people's congress.

He called on experts to explore a method to achieve balance between the amount of cars in the city and heavy air pollution in the area.

"The concentration of PM2.5 fell 37 percent in January year-on-year but that didn't cheer me up. Why? I don't know what might come later," Wang said.

He said cars are the top source of pollutants in Beijing, with the burning of coal the second biggest reason for the region's pollution.

The proposal has elicited an array of opinions from experts and Beijing residents.

Chang Jiwen, an environmental protection official at the Development Research Center of the State Council, said that although the city's legislature has the right to issue laws to protect the environment, the proposal involves limiting property ownership.

He said legislation with major ramifications should be proposed at the national level.

Liu Taigang, a professor of public administration and policy at Renmin University, suggested holding a full debate before a ban on the use of cars is made into law.

He added that if legislation is passes, families might purchase another car to circumvent the regulation.

Cui Na, who bought a car in January in Beijing, is not satisfied with the government's proposal.

"If it becomes law, would the transport authority give me a refund for the car-use taxes that I have paid?"