Jeff Speck recently published a fabulous new book entitled Walkable City: How Downtown Can Save America. I must put a disclaimer here that I have not, in fact, finished the book, but there are so many insights in the first few chapters that I couldn’t wait to write about the implications that these US-centered ideas can and should have on cities throughout the world. Couldn’t one write the same book on how necessary it is to build walkable cities in Lagos, Nairobi, or Port-au-Prince? I think anyone that has sat in the infamous traffic in any of these cities would agree with me when I say emphatically, yes.

And we need to ask these questions now. As The Economist pointed out a few months ago, “Sometime in 2013, whether by a birth in the Makoko slum or a job-seeking migrant stepping off a minibus at the motor-park, Lagos will overtake Cairo to become Africa’s largest city.” And yet, even that article talks about the need for better public transportation, without mentioning the simulatenous need for cities to both have public transport and to be walkable.

Why walkable? As Speck describes in detail, walkable cities make people healthier, happier, more productive, and wealthier. Literally. Just a few examples:

• Wealthier: Almost 85% of money spent on cars and gas leaves the local economy.
• More Productive: In Europe, you can have 5 meetings in different locations. In Nairobi, 2? If you’re lucky? This leads to measurable differences in productivity when comparing Portland, Oregon (very walkable) to Atlanta, Georgia (a city where most people drive.)
• Healthier: One study found in San Diego that 60% of residents in a low-walkable neighborhood and only 35% in a nearby walkable neighborhood. During the Olympics in Atlanta in 1996, hospitializations for asthma attacks actually went down, despite a temporary doubling of the population, because people decided to walk or take public transporation rather than drive (due to fear of traffic because of the crowds.)

In fact, he echoes many social scientists before him who have highlighted the evil impacts of suburbanization to an extent that makes you want to send policy makers from the 1950s onward to the International Criminal Court for crimes against humanity (ok, maybe that’s just me.) There are many examples of how policies have pushed suburbization over vibrant, walkable downtowns. One recent study, for example, shows how federal government support is skewed towards single-family homes, rather than multi-family developments (aka, apartment buildings that are prominent in condensed, urban areas. ) This is just one of many examples of active policy and financial support for sprawl from local, state, and federal governments for at least the past 60 years.

The good news? In the United States, the housing crisis has created an unprecedented opportunity for the market to shift, as people are ditching their big houses in the suburbs for small homes with shorter commutes – a trend highlighted by Brookings Fellow Christopher Leinberger. There is organic, bottom-up, market demand that is breaking through entrenched car and oil lobbies to finally encouraged real change to the way that we build cities in America. People now will pay a premium to live in walkable cities. As evidence a home with a high score on the popular website Walk Score can sell for 5 to 10 percent more than a similar house with a lower score (Speck 26.)  So demand works both ways – yes, many people want to live in big house with yards, but many people will choose a option that allows them to drive less, if given the chance.

The question then becomes, is the demand present in Lagos and Nairobi? I don’t think we know. There is an inverse relationship between wealth and demand for cars: the poorest people in any city or country desire to own cars because they are status symbols, while the richest people in these same cities reach a point where hours of traffic lead them in the opposite direction, wanting to live in areas where they can walk or bike to work. Another way to put this, quoting the blog This Big City, is that poor citizens in African cities “walk despite the un-walkable urban environment, not because of it.”

So how do we build on the organic demand for walkable cities driven by the wealthy in each city, while still ensuring that the benefits of walkability are available to all segments of the population? A contributor the magazine Intelligent Life recently asked this question to one of the world’s leading architects, Simon Foster. While Foster has done very little work in Africa, he did note that development of Africa slums require ‘a very different approach to the design-profession response to wipe it clean and superimpose another order, which completely disregards the fact that, notwithstanding the horrific deprivation, there is an underlying social order and an organic response to needs.’ Well said.  We need a better understanding of how bottom-up demand and consumer preferences can drive the creation of healthy, vibrant, and movable downtowns across income levels.

There are certainly policies that can both avoid top-down vast urban improvement projects while avoiding the temptation to actually support urban sprawl, thereby creating the vehicular nightmare that is getting worse by the day in cities around the world, especially those in Africa. Many of these policies may simply be the lack of policies – letting cities develop organically through the efforts of innovators and entrepreneurs. In perhaps one of my favorite books ever, Arrival City, Doug Sanders describes some of these policies through a poetic worldwide tour of urban migration. For example, ensuring that ‘slums’ include multi-use buildings where new arrivals can easily set up a shop or small restaurant, rather than high-rise apartment buildings with strict zoning restrictions, is one way to support entrepreneurship and keep cities walkable and economically vibrant – even in areas labeled as slums.

There is so much more to write and I’m not even half through Walkable City. What do you think are specific policies that can improve African cities?