Beijing may expand a campaign to urge people take public transport to work and could introduce totally car-free days ahead of the 2008 Olympics, an official said on Monday.

A traffic policeman puts on his gloves among the vehicles at Chang'an street ahead of the upcoming China-Africa Summit in Beijing November 3, 2006. Beijing is to restrict the use of vehicles by government departments and state-owned enterprises and shorten school hours to ease traffic congestion during the China-Africa forum, China Daily reported.[File Photo]

A voluntary effort over the China-Africa summit at the weekend to encourage people not to drive was successful, cutting down on traffic and clearing away pollution, said Du Shaozhong, deputy head of Beijing's Environmental Protection Bureau.

"We believe that cutting down on driving is helpful to the general Olympic spirit," Du told a press conference in increasingly rich Beijing where some 1,000 new cars hit the streets each day.

"I think drivers and the general public were quite enthusiastic about this campaign and I believe we could continue with this kind of activity."

More than 400,000 people signed a pledge not to drive during the summit, the Beijing government said in a statement.

About 40 percent of commuters took public transport as opposed to just under 30 percent at other times, said Liu Xiaoming, deputy director of the Traffic and Transportation Administration Committee of Beijing.

Three days of some of the strongest winds to hit the city this year also did their bit in helping to clear the air.

Beijing is spending $40 billion revamping its old-fashioned subway system, building new lines and improving rolling stock, as well as building new roads, highways and other infrastructure in preparation for the Games.

The government also sent mass text messages to mobile phones informing people of traffic restrictions during the Africa summit.

That and asking people not to drive to work were all good experiences for hosting the Olympics, Liu said.

"We will certainly make sure of good traffic conditions for the Games," he added.