Roads of redemption

THE wooden shacks are neatly grouped in blocks; fences separate lots; there is even the odd well-tended garden. As slums go, Brisas de La Popa is surprisingly organised. But as Miguel Villazon drives through this district on the outskirts of Valledupar, a city in north-eastern Colombia (pictured), he remains unimpressed. “Upgrading this neighbourhood will take years,” grumbles Mr Villazon, the mayor’s right-hand man. Streets will have to be widened, shacks moved and sewers put in. “Doing all this before people come, would be much, much cheaper.”

Like many cities in poor countries, Valledupar has grown in higgledy-piggledy fashion, from a town of 150,000 in 1985 to a city of nearly 440,000 now. Land was occupied before critical infrastructure was put in, often at great expense. But now Valledupar and eight other cities in Colombia and Ethiopia—to be joined by others in Ecuador, Mexico and India—want to show that urban growth need not be so disorderly. They are part of the Urban Expansion Initiative, an ambitious programme launched by New York University (NYU) to help cities make long-term preparations for their growth.

Between now and 2050 the number of people living in cities will grow from 3.9 billion to 6.3 billion. The proportion of urban dwellers will swell from 54% to 67% of the world’s population, according to the UN. In other words, for the next 36 years the world’s cities will expand by the equivalent of six São Paulos every year. This growth will largely occur in developing countries (see chart). But most governments there are ignoring the problem, says William Cobbett of the Cities Alliance, an NGO that supports initiatives such as NYU’s. Those that don’t often find urban migration unmanageable.

Some governments are trying to curb the growth of cities by imposing limits on movement and restrictions on land use. They fear plans that mark out land for future development will result in even greater migration. “Such plans are necessary as a safety net, but they could signal that a city wants to expand and attract even more people,” says Horacio Terraza of the Inter-American Development Bank.

Restrictive policies are doomed, says Shlomo Angel of NYU, whose research is the basis for the initiative. He and his colleagues looked at two sets of satellite images for 120 cities taken in 1990 and 2000. The result, set out in a book, “Planet of Cities”, was that both urban populations and land cover grew on average at the same rate in cities of all sizes (by 1.6% and 3.7% per year respectively) regardless of planning policies. Attempts to block growth mostly backfired. In Seoul, for example, a protected greenbelt did little to prevent sprawl, but led to astronomically high house prices in the centre.

A much better policy, says Mr Angel, is to “make room”—not with a detailed master plan of the sort that gave rise to ugly artificial cities such as Brasília, but with a “platform” that can be built upon like Manhattan’s now-famous street grid. It was adopted in 1811 and allowed the island to be developed over time. Today’s fast-growing cities should establish expansion areas that can accommodate expected growth, plan arterial roads and public spaces, and secure the rights for both, says Mr Angel. This way streets can be built and infrastructure put in as needed.

Of the five Colombian cities participating in the NYU initiative, Valledupar has made the most progress. Its mayor, Fredys Socarrás, is in a hurry. Elected in late 2011 on an anti-corruption platform, he has less than two years left in office (mayors can only serve one term in Colombia). Long-term planning, he says, is vital to re-establishing confidence in the city’s government. Valledupar is expecting to add another 200,000 people by 2040.

To accommodate them and future land needs, Mr Socarrás wants to allow the city’s area eventually to triple to 80 square km (31 square miles). His plan’s map is covered by a grid of big lines—future arterial roads, the guide rails of the city’s growth. They are meant to accommodate not only cars but important infrastructure of all kinds, from water pipes to bus routes. To ensure that these services can be easily reached from any point in the expansion area, the roads are spaced about 2km from each other.

In Ethiopia the impetus for city planning comes from the federal government. Mekuria Haile, the urbanisation minister, attended one of the initiative’s workshops in Addis Ababa last year. He faces a difficult task: the number of Ethiopians living in cities will triple by 2040, according to the UN. Awasa in central Ethiopia is expected to grow from about 200,000 inhabitants today to more than 1.2m by 2040. It is one of four cities that have already drawn up long-term plans. The government now wants all of the country’s cities to follow the NYU model. Ethiopia is able to move quickly because it has built a capacity to do urban planning in recent years, says David DeGroot, who helps the initiative on the ground. Local governments have been strengthened and a new university has trained hundreds of urban planners.

Ethiopia also benefits from having straightforward land laws. The government owns the land; it is only leased to those who use it. If a city wants to expand into a rural area, farmers must be compensated for lost income. So far, this has gone smoothly: rules are clear and payments generous. In Colombia the situation is more complicated. Cities have to make up their own rules for how land rights are secured and owners compensated. One possibility under discussion in Valledupar is to give owners tax breaks when they sell their land, which would be worth more once it is developed.

Long-term planners face other potential hurdles. In Colombia political transitions can be disruptive. Mr Socarrás’s predecessor did not care about urban planning and there is no guarantee that his successor will. “If the plan is not implemented before the mayor’s term ends, this could jeopardise the entire project,” says Nicolás Galarza, an NYU researcher who is working on the initiative in Colombia.

Cities have little choice but to try to channel growth. Slums like Brisas de La Popa can be upgraded, but in big cities this is more difficult. Bangkok, for instance, has grown without central planning. As a result, it has few arterial roads, no piped sewerage system and no network of water mains in many districts. But it does feature epic traffic jams, polluted groundwater and unstable land. “Whether we want it or not, urbanisation is inevitable,” says Mr Angel. “The real question is: how can we improve its quality?”