There are conflicting reports about whether a test run of traffic controls in Beijing less than one year before the 2008 Summer Olympics has been effective in improving air quality in the Chinese capital.
Chinese state media reported Tuesday that the city's overall air quality improved during the four-day test, which removed more than one million cars from Beijing's roads each day. The Beijing Environmental Protection Monitoring Center said the air quality was classified as "fairly good" during the four days.
But independent reports said a stubborn gray haze shrouded Beijing throughout the test period. The government's own statistics showed the air quality over the four days rated among the top 10 worst days of the month so far - slightly worse that the same period a year ago.
The State Environmental Protection Agency said Beijing's air pollution index was between 93 and 95 on the test days, with an index below 100 indicating good or excellent conditions.
The index hit 116 Tuesday following the test and was 115 the day before the trial began. However earlier in the month the pollution index had dipped as low as 42 and generally hovered in the 70's or 80's during the first two weeks of the month.
Some information for this report was provided by AP.