BEIJING, Dec. 18 -- The Beijing city government's latest indication of a possible subway fare hike has triggered heated public debate.

The local authorities are mulling proposals to raise subway fares to help ease heavy passenger flows in the rush hours, according to a working draft released by the Beijing Municipal Government on Friday.

In Beijing, a subway ticket at two yuan (0.33 U.S. dollars) allows passengers to ride on any line and make transfers. The rate, which has been in place since 2007, has long been the country's lowest.

In 2007, the city lowered the subway fare from 3 yuan to 2 yuan in a bid to ease road traffic congestion and to alleviate air pollution by reducing car use.

Beijing, home to 21 million permanent residents, currently has 456 km of subway lines in operation, carrying 10 million passengers daily.

Many local commuters question the government's intention behind the fare hike as they believe that it will have little effect in helping ease the rush-hour passenger flows.

"The price rise will have limited impact even if the fare is doubled or tripled," said Mao Muzi, who lives in the Huilongguan neighborhood in northern Beijing.

For office workers, who form a majority of passengers during the morning and evening rush hours, they are left with no better choices for their commutes as the roads are congested while taxi fares are expensive, Mao said.

In the rush hours, many commuters have to join long queues before even entering major subway stations, where they usually see several trains arrive and depart before they can get on one.

If the fare is raised substantially, then more will be encouraged to drive cars, adding further pollution to the already smoggy city, said netizen "Lengyuegengu" on Sina Weibo, the popular microblogging site.

"If the subway fare remains at low levels, then car use could be reduced, helping to clean up the dirty air," said another microblogger under the name "503257."

There are also supporters of fare hikes as the subway services are heavily subsidized, becoming a heavy burden for local fiscal expenditures.

It is estimated that total subsidies to Beijing public transport, which also includes the bus service, will exceed 18 billion yuan this year, the People's Daily, the flagship newspaper of the Communist Party of China, reported on Wednesday.

"As the market should play a decisive role, then a moderate hike is acceptable," said Sina Weibo user "Shenglou2013."

But some also urged the subway opearators to make their revenues and costs more transparent. "If the data is opaque, then how can a fare hike be justified?" asked "Weichen's microblog."