In a bid to improve air quality for the Beijing 2008 Olympic Games, city officials in Beijing recently banned more than a million cars from its roads.  For four days, traffic flowed freely, but smog still lingered, raising doubts to the success of the trial. Sam Beattie reports from Beijing.

China's reduced traffic congestion

With the ban in place [August 17th to August 20th], Beijing streets were noticeably less congested.  One-third of the city's cars -- some 1.3 million vehicles -- were taken off the street in a pre-Olympic trial to improve air quality.

Authorities decided only odd or even numbered car plates were allowed on the roads on alternate days during the four experiments.

Beijing environmental official Du Shaozhong says the results of the experiment are a positive step towards pollution-free Games. "The measures taken from the test results have been very successful for ensuring good air quality during the Olympics," he said.

Du Shaozhong

Traffic congestion is another concern during the Olympic period.  More than 1,000 new cars roll onto Beijing's streets each day.  The roads are filled with inexperienced drivers.  Gridlock is common.

And cars jostle for space with those left behind by China's rapid economic development.

Beijing's taxi drivers were thrilled with a break from the normal bumper-to-bumper traffic. Yang Fenglai says his income improved by more than 30 percent.  "Before, inside the city center, it was almost impossible to drive. It was start-stop all the time. Now like this, it is extremely refreshing."

China's regular traffic congestion

Many car owners were forced to use public transport, crowding the extra buses and subway trains put on to cope with the increase in passengers.

Those, like Zhou Fang, faced longer commute times and cramped transport. "A voluntary scheme would have been better . The government could have given a certain amount of subsidies or incentives, if you volunteered not to drive one day."

While the test certainly reduced congestion, it did not get rid of the haze that hangs over the city. 

As the games get closer, there is still a long way to go before athletes will be breathing clean air during the Olympics.