Beijing yesterday announced a drill to test the effectiveness of the Olympic host city's efforts to improve air quality and ease traffic congestion.

From August 17 to 20, about 1.3 million vehicles - nearly half of the total 3 million in the city - will be ordered off the roads as part of pre-Olympic tests, according to the capital city's environmental and traffic authorities.

On August 17 and 19 (Friday and Sunday), only vehicles with the license plate number ending with the odd numeral will be allowed on the roads.

On August 18 and August 20 (Saturday and Monday), it's plates ending with an even number.

The rule applies to Beijing-registered vehicles as well as those from outside the city.

Du Shaozhong, spokesman for the Beijing Environmental Protection Bureau, said air quality will be monitored during the vehicle-reduction days.

"Let's see the correlation between air quality and the number of running vehicles," he said.

"Data from the tests will be collected and analyzed to improve air quality," Du said, adding vehicle emissions are a leading cause of urban pollution.

In addition to the 27 air quality monitoring stations spread across all the 18 districts and counties, three new stations and two new mobile monitor vehicles will be put to use, he added.

Vehicles which will be exempt from the drill will include those of the police, ambulance, fire, postal and breakdown services and the public transit system as well as those belonging to embassies and international organizations.

Zhai Shuanghe, deputy director of the Beijing Municipal Traffic Management Bureau said the drill will test the city's public transport.

Rush hour services of the bus and metro systems will be extended to three hours, 6:30 AM to 9:30 AM, from the usual two hours, 7 AM to 9 AM.

Civic servants are supposed to arrive in office half an hour earlier at 8 AM, and shopping malls will open doors one hour later at 10 AM.

Currently, the public transit system carries 31 percent of the traveling public and is the most popular means of transport after walking.

Beijing runs 19,105 buses, two metro lines and two light rail transits lines.

During the test period, the public transit system will operate at full capacity. Besides, another 700 to 800 backup buses will be used, Zhai said.

Some cities around the world - such as Athens, Manila and Sao Paolo - restrict vehicles according to odd or even numbers on license plates.

(China Daily August 10, 2007)