Columnist: How to Plan Cities for 2.7 Billion More People

NAPLES, Italy -- Where in the world -- literally -- will affordable, developable land be found to house and service the stunning population growth of world cities, now estimated to rise from 3.6 billion souls today to a projected 6.3 billion by 2050?

Will cities move aggressively enough to gain clear control of outlying land parcels so they can plan ahead for roads and infrastructure, and stop rampant land speculation?

The issue bubbled to the top at the recent World Urban Forum of more than 8,000 public officials and other urbanists convened in Naples under sponsorship of UN-Habitat.

As Joan Clos, Habitat's executive director, put it: "If city expansion is not planned, well, it's going to happen anyway. Cities need planned extensions -- otherwise you'll have people living in slums. And to correct that will be very expensive, and it will be a mess."

But how can cities cope -- smartly? Shlomo "Solly" Angel of the Lincoln Institute of Land Policy brought unique research on that topic to Naples. He noted that most people assume that cities, growing especially rapidly in Africa and Asia, are getting much more densely packed together. Pictures of frightfully crowded slums only confirm the impression.

But Angel painted a different picture. With use of census population data and satellite imagery tracking changes in 120 major world cities between 1990 and 2000, he found they were expanding their territory on an average of twice as fast as their populations were growing. Census maps of 30 large global cities from as early as 1800 illustrate the same phenomenon -- humans, as their living standards rise, opting for dramatically expanded amounts of living space.

Angel calls this "the inevitable expansion proposition" -- so inherent in human nature it can't or shouldn't be altered. In his new book, "Planet of Cities," he dismisses the U.S. smart-growth movement as "purist," "uninformed" and a misguided "containment" approach that shouldn't be applied in the developing world.

Angel's prescription for new world cities -- medium-to large-sized metropolises, as well as hitherto obscure towns only recently reaching city dimensions -- is to acquire vast amounts of land on their periphery for future expansion. He'd have the cities divide the new lands into a master-arterial grid of superblocks one kilometer (1,100 yards) square. Developers could then carve territory out of the blocks for housing and commercial projects. Plus, he'd have the cities reserve adequate open space, a perennial wish of city dwellers, in each superblock.

The core idea makes a lot of sense -- acquiring land, while it is inexpensive, and plotting it to create coherent neighborhoods for settlers still to come.

Still, there are issues. Top example: Where's the money? Today's city halls, struggling to serve the populations they already have, will find it tough to find the funds -- or muster the political will -- to buy up large swaths of rural territory they may not need for years to come. Plus, if the city is one of those already hemmed in by other towns, however small, it may be unable to expand at all.

Second, why (BEG ITAL)not(END ITAL) plan for reasonable compactness, creating livability without unnecessary sprawl? -- a point UN-Habitat's Clos stresses.

Third, must farmlands near cities be mindlessly sacrificed for urban growth? Often they are in especially fertile river valleys. Angel's not concerned, asserting the planet has enough reserves of cultivatable lands to feed mankind in perpetuity. Others might demur, noting recent years' alarming spikes in international commodity prices, plus the danger of climate change disrupting food production necessary to feed the billions of new city dwellers.

Then there's the issue of transportation. Angel recommends that the roadways around the superblocks should be very broad -- wide enough for bus lanes, bike paths, a median, plus several lanes for auto and truck traffic. He does acknowledge that without strong political alliances in cities to introduce and strengthen public transportation, private motorized vehicles will rule the day.

Superior strategies might be devised. New Urbanist architect-planner Peter Calthorpe, for example, suggests that new urban neighborhoods such as Angel's superblocks should include, from their start, totally auto-free boulevards. Why? To assure a shared, amenable environment for pedestrians, cyclists, residences and shops. The boulevards would be open only to those users, plus bus rapid transit lines. Cars and trucks, with their noise and pollution, would be relegated to parallel one-way streets. Public transportation would become a keystone, not a maybe alternative for cities' expansion.

Angel acknowledged some barriers at the Naples sessions, adding: "I'm dedicated to getting this done in a few places. Just to protect the right-of-way and protect some open spaces. ... The whole idea is protection."

What is certain is that he's onto a key, unavoidable 21st-century issue. It's one thing to wonder in awe about (BEG ITAL)2.7 billion(END ITAL) still-to-arrive city dwellers. It's another to ask just how cities can create livable "people space" for their torrents of newcomers.

Neal Peirce's email address is

(c) 2012, The Washington Post Writers Group

The opinions expressed in this column are not necesssarily those of the National League of Cities.