For many planners, tackling Beijing's congestion will take more than building a better subway. Li says the underlying problem was the concentration of government, universities, and companies in Beijing's relatively small historic core.

Beijingers, he said, must travel farther each day than their counterparts in other major cities, such as New York and Tokyo, making painful commutes all but inevitable. A commuter living at Nanshao, at the end of the new Changping line, for example, would need over an hour just to get on board Line 2, the circular line that circumnavigates the city center.

Long trips are also making it harder for Beijing commuters to use bicycles, once the main form of transport in most Chinese cities. Zhou says bicycles and bicycle lanes were being crowded out by the proliferation of private cars, which more than doubled in Beijing during the past 10 years.

"In Europe," he says, "the bicycle is coming back, but in China, we are losing bicycles, especially in the last decade. We are losing bicycles lanes."

Li says that the subway system now serves less than half of Beijing's residents. In recent studies, his department found that half of all trips in Beijing are taken in private cars, making congestion worse than in larger cities, even those with more cars.

"Right now, Beijing doesn't have a very good public transport system. The number of cars in Tokyo is much higher than Beijing, eight million as opposed to five, but in Tokyo, 90 percent of commuters take public transit."

Experts are more optimistic and confident that Beijing can eventually "build out" of its current crisis, using a combination of new approaches to transportation now being tried in cities around China, and, changes to the way space is used in Beijing.

But, Li says, the process will be difficult and slow.

"Don't put your expectations too high, no way the problem can be solved in a few years," he says. "People will suffer, even as we fix the problem, and have to change their lifestyle, for sure."

First on the list is reversing the trend toward driving to work.

Doing so, Zhou says, is more than just an engineering problem. In order to create new bike lanes or routes for bus rapid transit, a system that gives long-distance buses their own lanes in order to speed their travel though heavy traffic, planners will have to take room away from cars.

"Surface transportation is often political," he says. "Politically, decision-makers don't want to allocate surface to public use over private."

In the past year, the city of Beijing has begun trying to get cars off the roads, putting strict rules on car ownership and licensing. Residents without Beijing hukou or household registration are no longer allowed to drive their cars within the city limits.