Beijing launched its inaugural "no-car day" Monday to combat the city's worsening pollution woes, but traffic was as grid-locked as ever and the grey air remained dense with exhaust fumes.

More than 250,000 drivers have committed to leaving their cars at home one day each month, organizers said as the voluntary campaign that is based on a similar French program got underway on World Environment Day.

However there were few signs of any significant decrease in traffic on Monday, with drivers either saying they were not aware of the campaign or simply could not do without their vehicles.

"I heard about no-car day on the radio but I had to drive because I need to run some errands later today," said a manager with a foreign company surnamed Lu, who drives a Volkswagen Jetta, in Beijing's central business district.

A parking lot attendant surnamed Lin who has worked at the same car park for seven years said she had seen just three or four fewer private vehicles than normal arrive on Monday.

The 250,000 drivers who had committed to not driving represent just under 10 percent of the 2.6 million cars that are on Beijing's roads. But even if all of those drivers actually did not drive to work once a month, that benefit would be quickly be eliminated, with government figures showing an additional 1,000 cars are taking to Beijing's roads each week.

By the time of the Olympics in 2008, the government estimates there will be 3.5 million cars in Beijing.

The Beijing Environmental Protection Bureau, which is organizing the "no-car day" campaign along with private motoring clubs and non-government groups, emphasized Monday the consequences of the city's growing car population.

"The pollution caused by motorized vehicles makes up 30 percent of the air pollution in Beijing," Du Shaozhong, vice head of the bureau said in an interview on China Central Television. "If every driver agrees not to drive their vehicle one day a month then we could reduce air pollutants by 44,000 tons a year."

Du said cars were one of the capital's three biggest causes of the city's pollution, alongside dust and coal burning. Du reiterated the government's concerns that the city was not meeting clean air targets that were set as part of a "blue sky" campaign launched in 1998.

Du said this year's target of 238 "fairly good" air quality days would be difficult to reach. From January through April, Beijing enjoyed only 51 "blue sky days," 16 less than the same period last year, according to figures released last week. But while Monday's no-car campaign appeared to fail to get out of first gear, the congested roads appeared enough for some to give up the dream of car ownership.

"I don't know how to drive and looking at Beijing's traffic situation, I don't want to learn how to drive either," Liu Lu, 25, an administrative assistant who takes the subway to work, told AFP.