Soaring housing prices and traffic congestion are among the major bottlenecks that harass Beijing's social and economic development, Mayor Guo Jinlong said at the municipal parliament session opening Sunday.

"We are under heavy pressure to stabilize housing and other retail prices, and optimize investment structure, now that a comparatively high proportion of investment goes to the real estate sector," Guo said in his government work report submitted to the annual session of the Beijing Municipal People's Congress, the local legislature.

This year, he said the city government would take strict measures to regulate the real estate market, ensure stable and orderly land supplies and curb speculative investment to keep housing prices from soaring further.

The government plans to build more affordable houses for the low-income groups. "We will build or buy in 200,000 affordable apartments this year and hopefully half of them will be ready to move in by the end of the year," said Guo.

Besides housing, Guo said the city government would continue to rein in retail prices, and keep the consumer price index (CPI), the main gauge of inflation, to around 4 percent.

He estimated Beijing's CPI was within 3 percent last year.

The mayor said to ease congestion remained a pressing job in a city with 20 million people and 4.8 million vehicles, but vowed to "effectively curb congestion" in five years.

In what Chinese Internet users described as "the toughest congestion-tackling measures in history," Beijing began to limit this year's total issuance of new car license plates to 240,000, or one third of the 2010 volume.

Starting from Jan. 1, car buyers in Beijing have to apply first and then draw lots before they can obtain a car license plate.