"The single pricing system is easier to adopt and cheaper for passengers. As more subway lines are completed, more people will choose to take the subway, the above-ground traffic jams will be eased and air quality will be better," said Liu Tongliang, head of the Beijing Municipal Transportation Administration Bureau.

Taking into account the inevitable rise of the number of subway passengers, local traffic authorities have promised to increase subway trains and shorten intervals between trains to boost the transport capacity.

Meanwhile, Liu said the government would increase expenditure on public transport by 1 billion yuan annually after the single price scheme is adopted.

Road congestion has been a major problem yet to be solved for the Chinese capital, which now registers more than 3 million vehicles, and citizens have been urged to take public transport to ease traffic pressure.

The municipal government has been giving discounts of up to 60 percent for residents, and even 80 percent for students, for bus tickets since the beginning of this year to encourage people to choose public transport.

The city aims to raise the proportion of citizens choosing public transport from about 30 percent to more than 40 percent by 2010, according to Liu Xiaoming, deputy director of the Beijing Municipal Commission of Communications.

To achieve this goal, Beijing will raise the number of buses from 18,000 to 21,000 by 2010, and extend the metro line from present 114 km to at least 270 km, Liu said.