Cities without highways?

A future possibility, some say

Matt Dietrichson, Aug 24, 12.

A prominent American architect-planner believes expansive urban highways may not make sense in the mega-cities of the future, according to Citiwire:

Imagine cities built for billions of people without a single freeway. No “flyovers.” No elevated roads or canyon-like depressed super-roads.

Advanced by American architect-planner Peter Calthorpe and Colombia’s former Bogota Mayor Enrique Peñalosa, the idea caught the imagination of an international forum of city experts and advisers meeting at the Rockefeller Foundation’s conference center in early August.

And why?

First, numbers. World cities (especially those of Asia, Africa and Latin America) will grow a stunning 72 percent by 2050, from today’s 3.6 billion to 6.3 billion people, more than the total world population in 2002. The task of creating livable environments for the newcomers will be made even tougher by freeways that consume big chunks of cityscape, cut through and often isolate poor neighborhoods, and pollute prodigiously. Sold as congestion relief, urban freeways encourage more auto use and end up triggering some of the most massive traffic snarls known to humanity.

Second, and sadly, limited-access superroads, with extraordinarily high construction costs, soak up public revenue that could go into schools, housing, libraries and public health to improve the lives of millions of families scraping by at subsistence levels.

Instead, those in the developing world who gain from the superroads are most often the affluent, using them to commute between city centers and gated communities miles away. The superroads produce waves of sprawl and chiefly benefit the international consultants and construction firms that push them.

The Bellagio conference heard bright counterpoints.

A first is that cars – and significantly high numbers of them – can be accommodated on regular city streets. Broad boulevards around the world do this. Paris’ famed Champs Elysees, for example, isn’t thought of first as a roadway, but in fact has eight lanes of traffic.

“There’s nothing wrong with cars,” says Peñalosa, “it’s how they’re used.” In crowded developing world cities with staggering millions of residents, a European- or U.S.-style “every-man-owns-his-own” auto culture just can’t be imagined.

Rapidly growing 21st-century cities, providing they make smart, early expansion plans, can materially improve their prospects of achieving workable street networks.

Calthorpe, for example, suggests that freeway-free cities could be planned with a broad network of car-less avenues, each offering generous space for walking, biking and exclusive bus lanes, an environment perfect for apartments and shops. Each such avenue would be separated a few hundred yards in each direction from parallel one-way streets that accommodate cars and trucks.

If the central avenues of those neighborhoods can really be kept auto-free, notes cities expert Nicholas You, the absent roar of motors and tires might let architects design buildings for natural ventilation, which could mean savings on energy use for air-conditioning.

So what’s the secret to creating such a freeway-free, democratic vision of the future city for all? It’s clearly to get ahead of the private sector land-grab that so frequently accompanies rapid-growth cities.

That’s the rub. The only way to insure against land speculation and bad use, says Peñalosa, “is government control of expanding land use to prevent crazy sprawl.”

Or as U.N.-Habitat Director Joan Clos said in closed-circuit remarks to the Bellagio conference, steps should be taken to prevent inefficient development along corridors, to create and protect public spaces, to put legal limits on what’s buildable and to create a logical street layout that may stay in place for 200 or 300 years.

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