During the 2008 Olympics in Beijing, the city implemented a rationing policy that restricted road use to cars with specifically numbered license plates: one day, cars with an even number at the end of their plate were able to use the road; the next day, cars with an odd number were allowed to drive. Last weekend, the Chinese city of Baoding revived the measure in a trial attempt to reduce traffic and decrease pollution.

China Daily reports that use of Baoding's Second Ring Road on Friday between the hours of 7AM and 8PM was restricted to those of the city's 1.92 million cars with an even number at the end of their license plate. The following Saturday, the roads were only open to cars with an odd number at the end of their plate. Buses and public service vehicles such as ambulances were still allowed to use the roads regardless of their license plate number.

Cars with even numbered plates could use the road on Friday; cars with odd numbered plates on Saturday

Baoding's trial comes after reported governmental pressure on cities to reduce their pollution from dangerous levels. China Daily reports that the heavily polluted cities of Handan and Xingtai conducted similar tests in October, but that that neither city has yet released plans to continue with the license plate bans. Lanzhou has adopted the measure for a longer period: China's People Daily reports that the city — stricter than most Chinese cities about its air quality after ranking as the city with the country's worst air quality in a 2011 World Health Organization survey — will use odd-even license plate restrictions until January 10th next year.

Baoding's air was reportedly half as polluted by 4pm on the day the trial began

Elsewhere in the country, other measures have been introduced to curb car use and resultant pollution. Both Beijing and Shanghai use a complicated lottery process to earn a license plate. As Bloomberg Businessweek reports, these plates can often cost more than the car itself. Smaller cities, too, are adopting suites of anti-pollution measures aimed at road users. Guangzhou started using odd-even license plate road rationing after the Asian Games in the city brought increased traffic.

China Daily reports some Chinese citizens argue the scale of license plate restrictions is too limited, and that the pollutants from coal burning will far outstrip any gains made in reducing road traffic. Road restrictions might be a more low-tech answer to curbing Chinese emissions than a Dutch designer's desire to 'vacuum' pollution away from the country, but they may actually provide a quicker, temporary fix to harmful levels of pollution: Baoding's air was reportedly cleaner by 4PM on Friday, dropping from a "severe pollution" air quality index to "lightly polluted."