Beijing officials are mulling limiting the number of cars on city roads in order to ease worsening traffic congestion, according to state media (report in Chinese).

At a forum on urban development, Liu Yumin, deputy director for the Beijing Planning Commission, said, “Traffic problems will not be resolved by gains made in other areas.”

It’s the first time a city official has publicly mentioned plans for limiting the number of automobiles in China’s capital, and could mark a change in gridlock-fighting policy that is tougher than existing programs.

Until now, officials have been loath to put restrictions on car owners because the state-owned auto industry is a powerful lobby, and the car industry is seen as a pillar of economic growth. That dynamic is changing. Officials are alarmed by congestion worsening despite big improvements in public transportation such as new subway and bus lines.

About 2,000 more cars are added daily to Beijing’s streets. The boom is fed by demand from China’s rising middle class. Starting in 2008, authorities implemented a system to take out about 20% of the city’s cars. Drivers would have to leave their cars behind once a week, depending on the last digit of the license plate. But that appears to have been overwhelmed by the sheer increase in new cars.

The car boom is contributing to poor air quality. Traffic jams are especially bad because stop-and-go causes more pollution than smooth travel.

China’s mounting transport woes drew international attention in September when trucks laden with coal and other goods got stuck in a 10-day traffic jam on a highway from Inner Mongolia’s coal regions to Beijing and eastern ports.

Authorities have announced a 10 billion yuan, or $1.5 billion, expansion of part of that highway. Consolidation of coal mines in nearby Shanxi provinces, and the opening of new mines in Inner Mongolia led to a nearly 50% increase in the volume of coal ferried on that highway, contributing to the jam.