Driving home the green car message

The clear blue skies during the Beijing Olympic Games were impressive not only for foreign visitors.

The clean air even led to local people to call for an extension to the two-month odd-even license plate restriction that allows the city's 3.3 million private car owners to drive only on alternate days.

After years of efforts to improve air quality, emergency pollution controls like the traffic restriction worked wonders. It brought air cleaner than many people had expected.