Beijing - A four-day driving ban that took 1.3 million cars off the road each day in Beijing hardly improved the air quality in one of the world's most polluted cities, according to an Environment Ministry assessment released Monday. The ministry said the city's air-quality over the weekend hovered between 91 and 95 points on an index in which readings of 51 to 100 represent "fairly good" air quality.
Those numbers were better than the 115, or "slightly polluted," reading on Thursday, before the ban went into place, but worse than the eight days before that when the index read between 56 and 88, possibly because of more frequent rainfall.
Monday marked the last day of the driving ban, during which the metropolis of 15 million people barred cars with odd- and even-numbered license plates from the roads on alternate days.
The ban was conducted as a test of measures being considered for implementation during the Beijing Olympic Games next August. Authorities are seeking to improve the city's air quality and reduce the traffic on its increasingly crowded roads.
Despite the disappointing air-quality results, which saw a pall of smog still hanging over the Chinese capital, an engineer with the municipal environmental regulatory agency described the exercise as "an effective measure" because it had at least seen an improvement over Friday's air quality.
The trial run was a more obvious success in reducing traffic and traffic jams.
Besides the traffic ban, Chinese authorities also plan to close factories during the August 8-24, 2008, Games.
The largest driving restrictions ever seen in Beijing were implemented amid growing international concern and criticism of Beijing's poor air quality and its effects on Olympic athletes.