BEIJING, Nov. 26 -- The proposal for a daily ban on half of Beijing's cars needs to pass detailed scrutiny before receiving a government response, a senior official of the Chinese capital said on Wednesday.

Beijing, China's most congested metropolitan, saw minimal traffic during the Asia Pacific Economic Cooperation (APEC) week earlier this month, as half of its cars were banned from the roads each day.

Cars were only allowed to be driven on alternating days based on odd or even license plates during the week.

The car ban not only gave Beijing free flow of traffic, but also helped lift the city of 21 million people out of persistent smog.

With traffic congestion and smog returning to Beijing after the APEC meeting, some residents have started to call for the government to make the temporary administrative order a routine practice.

Beijing Vice Mayor Li Shixiang said the government needs to research and scrutinize such proposal before any response.

The government also needs to hear different voices, Li said.

Some residents argue that if the proposal were to be adopted, rights to property and the road would be overly restricted. Beijing's public transportation would not be able to cope with the passenger volume increase if half of the city's cars are banned.

Vehicle emissions account for 31.1 percent of local smog sources, according to Beijing Environmental Protection Bureau.