SHANGHAI: A new campaign to ban smoking in taxis is part of a wider push to clean up the city's image before the 2010 World Expo.

The Shanghai Dazhong Taxi, a taxi company, said drivers found smoking in their cabs could "possibly" be fined or even temporarily banned from working.

Signs have been placed in all of the taxi company's 9,100- strong fleet saying "No Smoking in Dazhong Taxis, Welcome to Shanghai World Expo".

"For a long time, the sanitation of the city's taxis has been affected by the smell in some cabs," said an official surnamed Zhao with the company.

"We hope the sanitation of cabs in the city will be improved through our no-smoking campaign, which is a mutual benefit for both drivers and passengers."

Liu Zheng, an office worker who often takes cabs, said the campaign was a positive one.

"Cigarette smoke contains many types of carcinogenic particles which can become trapped in air-conditioners. It is also hard to remove the smell from cars even with all the windows opened."

Dazhong said it would closely monitor the campaign's progress.

Drivers caught smoking will undergo the company's training and inspection program.

Cabs found to have cigarette odor will be "called back", Zhao said.

"Of course, we will behave according to the company's regulation, but how about passengers' smoking in the cab?" asked one taxi driver who declined to be named.

No penalties have been drafted for passengers who breach the no-smoking rules.

Instead drivers will be responsible for "persuading" them not to smoke.

Many taxi drivers smoke to relax from working long hours. The official conceded it would not be an easy task to achieve a total smoke ban in a short timeframe.

"Promoting non-smoking taxis in the whole city is a long journey," Zhao said. "Despite having a long way to go, we are confident of fulfilling our "smoke-free taxi" program in the city through our diligence."