An odd-even license plate number system was introduced to allow cars to be driven every other day in peak hours in some congested areas.
Beijing opened five new suburban subway lines on Dec. 30 with a combined length of 108 km, bringing the city's total number of subway lines to 14 and the total length to 336 km.
Beijing was building more subway lines, Li said.
The number of lines in the city would reach 19 by 2015. Then, their combined length would total 561 km. By 2020, the total subway length would increase to 1,000 km, she said.
"Developing public transport, especially rapid rail transit, is an important move for Beijing to ease traffic congestion and improve urban functionality," she said.
Li Feng, who lives in Daxing, a suburban district in southern Beijing, told Xinhua Wednesday that he had felt the positive changes in Beijing's traffic.
"I used to drive at a speed of only 20 km per hour when I entered and left the city in the morning and evening rush hours, but now I can drive at 40 km per hour," he said.
Yet many people are waiting to see the long-term effect of the measures as Beijing still faces pressure from the huge demand for private cars.
The Beijing transport authority on Sunday revealed it had received 215,425 new car license applications, after this month's application period closed late Saturday night.
But only a tenth of the applicants will get license plates this month, after a lottery is held on Jan. 26.