Yuelai Eco-city / Calthorpe Associates

Urbanization in China is the single biggest human migration in history. To accomodate the millions coming in from the countryside each year, China's cities are tearing down their old human-scale, socially-rich neighborhoods, with their meandering, bicycle-friendly streets, and putting in highways and incredibly isolating towers set amid vacant-feeling "super blocks." These are places only Le Corbusier could have loved. Or at least that's the image some see in the West. At the World Urban Forum in Medellin, Colombia, a group of innovative Chinese urban planners explain how some of the latest "eco-cities" as well as design interventions in existing cities may help some Chinese mayors see the wisdom of sustainable urban development and taking those super-blocks down to size.

Dongquan He, with the Energy Foundation, said China now has more than 660 cities, with 20,000 more towns under construction. Over the next 25 years, 400 million more Chinese will move into cities. And by 2050, China will be 75 percent urban.

As China grows at incredible rates, its cities have created very wide streets that connect super blocks. "These have just a single function, moving from A to B. You really have to use a car to get around." These planning decisions have also resulted in signficant environmental damage. The air in so many Chinese cities is basically unbreathable because cars have been let loose. He said: "China's development problem is the super block."

The Energy Foundation has come up with a whole set of criteria to explain urban sustainability to China's mayors. The principles are well considered: places should be walkable; bicycling should be prioritized; networks of streets should be dense; public transit should be high-quality; developments should be mixed-use; and parking should be regulated.

To test these idea, He and his team became involved in a new thousand-hectare eco-city inYuelai, Chongquing, one of the country's mega-cities (see image above). He's group worked with Calthorpe Asssociates and the eco-city developers to preserve the existing landscape. "We didn't violate the natural systems." They then created a plan that reduced the size of the average Chinese super block, allocating density near transit, creating small town-centers with public space every 500 meters, and also smaller grid spaces that fit high-rise, mid-rise. and low-rise buildings together in a dense, walkable street network. Parks and greenways connect people to the harbor, and a custom-designed streetcar system will also improve mobility. But He admitted that with this kind of huge development, "it's hard to created the small spaces people like." Indeed, in these images, the blocks still look a bit super.

Yuelai Eco-city / Calthorpe Associates

Yang Lou with the China Sustainable Transportation Center outlined his organization's work with the Chenggong New Town, in Kunming, which in China's southwest. He and his team are tackling "super blocks that didn't feel safe crossing." They helped increase the road network density by narrowing the streets and sidewalks considerably to improve the human fabric. Development is also now clustered around transit stations.

For EMBARQ China's director, Haitao Zhang, the aim is to transform Qingdao, a major city in the northeast, through his Qingdao Low-carbon Sustainable Transportation study. Zhang has worked on reconnecting land use and transportation planning, putting stations where there is demand, and breaking the siloed approach to the problems of sprawl in the local government. EMBARQ is also planning a slew of "small-scale urban interventions" to improve the streetscape, turning super blocks into outdoor cafes and pedestrian-friendly plazas.

To learn more about the state of China's cities, see a new report presented by Shi Na, with UN Habitat and the Urban Planning Society in China.