But the debate over motoring restrictions could point the way to the lasting legacy of the Olympics: meaningful public discussion on what sort of development the Chinese want.

Zheng Yongnian, director of the East Asian Institute of the National University of Singapore, predicted that China would feel greater pressure after the Olympics as the people questioned whether the air quality and traffic will slide back to the pre-Olympic state.

"After the Olympics, more attention would be paid to changes in China...because China has become a power in the eyes of the West. They would monitor or supervise the development of this important country," said Zheng.

He suggested China treat them with a calm and confident heart, because criticism is beneficial to China and makes it do better.

While the Olympics infrastructure has pointed the way, the clean air has shown clear evidence of a better way forward and the need for public participation to achieve a better end result.

Alert to the drastic environmental price of its economic progress, China has found central policies of pursuing sustainable development obstructed by local governments, which still seek GDP growth at all costs.

Most of the capital invested in the Games was spent on infrastructure, which has helped to shape and plant a more important environmental awareness among the public.

Three subway lines and a 28-kilometer light rail linking the downtown with the airport extended the city's total length of track to 200 kilometers, accompanied by a new Beijing-Tianjin intercity express railway and new bus lines. The new Terminal 3 has more than doubled the capacity of the Beijing Capital International Airport.

The improvement in public transport has helped millions of residents in their daily commute, and the city's traffic authorities aim to boost the proportion of people relying on public transport from 35 to 45 percent.

The Olympics has also left Beijing with a series of spectacular sports venues.IOC president Jacques Rogge listed these venues as an important sporting legacy for the country, but these structures, mostly combinations of imaginative architectural designs, advanced building technologies and comprehensive energy-saving systems, could have a deeper influence.

The National Stadium, or "Bird's Nest", is regarded as a template for water conservation, with 70 percent of its water consumption coming from recycled water, and the neighboring Water Cube also boasts sophisticated water recycling and solar energy technologies.