Beijing will ban half of all cars from the road from Aug. 20 to Sept. 3 to ease traffic during the IAAF World athletics championships and the World War II victory parade.

Cars will be allowed on alternating days based on odd or even license plate numbers during the period, the municipal government said. The same ban was used last year during the Asia Pacific Economic Cooperation (APEC) meetings in Beijing.

The car ban is expected not only to give Beijing a more free flow of traffic, but also improve the air quality.

Eighty percent of official business cars will also be off the road, said Rong Jun, spokesperson for Beijing's commission of transport.

Factories will be closed during the period to ensure clean air for both of the events, said Yu Jianhua, chief engineer of Beijing Environmental Protection Bureau.

Jobs which raise dust at construction sites will also be suspended during the period. Trucks carrying construction raw materials will be banned from the roads. Other delivery trucks will not be affected, Rong said, adding that the number and frequencies of buses will be increased.

Beijing has shut down two coal electricity plants this year, cutting 4.6 million tonnes of coal burning; scrapped 178,000 vehicles; upgraded 8,800 diesel powered buses; and closed 186 polluting factories, Yu said.

The IAAF championship will be held in Beijing from Aug. 22 to 30.

The military parade on Sept. 3 in Beijing is part of China's commemorations of the 70th anniversary of victory in the Chinese People's War of Resistance Against Japanese Aggression.