WALKABLE CITY: How Downtown Can Save America, One Step at a Time. By Jeff Speck. FSG. 312 pages. $27.

If you had to come up with one quality that makes Charleston such a pleasant place to live, what would it be? The temperate climate? The stellar restaurants? Our historic buildings? The youthful energy of a college town?

Or is it something else, an often overlooked feature that makes the city feel like it belongs to us and that we belong to it?

Perhaps it is Charleston’s walkability. The idea that a metropolis that invites people to walk, to use their own two feet to get around, can be the linchpin of a functional, and fun, city, is the thesis of Jeff Speck’s brilliant and companionable new book, “Walkable City: How Downtown Can Save America, One Step at a Time.”

“Get walkability right and so much of the rest will follow,” says Speck, a city planner and co-author of “Suburban Nation: The Rise of Sprawl and the Decline of the American Dream” (2001) and “The Smart Growth Manual” (2009).

“Walkable City” is part manifesto, arguing for rebuilding cities to promote walking, and part manual on how to get it done.

To the detriment of our nation’s physical and economic health, American cities have abandoned the infrastructure that creates sidewalks filled with people. Instead we have standardized wide, treeless roads and huge surface parking lots, “auto zones in which pedestrian life is but a theoretical possibility,” writes Speck. He quotes a study that found “an hour spent driving triples your risk of heart attack in the hours that follow.”

Another study notes that transportation costs have doubled in the past half-century, now typically absorbing more than 20 percent of an American family’s income. The pity is that walkable neighborhoods have large economic advantages over car-dependent locales, a fact attested to by the growing demand among millennials and empty-nesters for housing in city centers.

Speck spells out his “General Theory of Walkability” in the first few pages of the book, proposing that any journey on foot must be “useful,” meaning that most of what is needed day-to-day is nearby; “safe,” so that pedestrians won’t be run over by motorists; “comfortable,” which requires streets to feel like “outdoor living rooms”; and “interesting,” because we need diverse facades and numbers of people to be entertained.

He then enumerates what we can do to create these conditions.

His “Ten Steps of Walkability” — including “Step 2: Mix the Uses,” “Step 6: Welcome Bikes” and “Step 8: Plant Trees” — are laid out with humor and tact and make “Walkable City” much more than a lament for where we went wrong.

This is a handbook for remaking our urban centers into genial places to live and work. The author rebuts common misconceptions, explaining why, for example, building additional highway lanes creates more traffic due to a phenomenon called “induced demand.”

“Walkable City” is at once entertaining and enraging, its pages dotted with jaw-dropping statistics.

“Step 3: Get the Parking Right,” based largely on the work of Donald Shoup, UCLA’s “prophet of parking,” offers a disturbing picture of how much America’s dysfunctional parking policies really cost. Every purchase we make includes a subsidy for “free parking,” the kind you find surrounding the local mall. Added up, the subsidies amount to hundreds of billions of dollars a year, a price tag on par with the national defense budget.

Shoup estimates that “the cost of all parking spaces in the U.S. exceeds the value of all cars and may even exceed the value of all roads.” Let that sink in.

With every page Speck artfully unfolds the case for a new pedestrian-friendly paradigm. “Walkable City” relies heavily on the work of others, notably Jane Jacobs’s seminal “The Death and Life of Great American Cities” (1961), David Owen’s “Green Metropolis” (2009) and Shoup’s “The High Cost of Free Parking” (2004), as well as Speck’s previous books, co-authored with Andres Duany and Elizabeth Plater-Zyberk.

Acknowledging the shoulders he stands on, Speck demonstrates that the notion that cities can be friendly to the people who live and move around in them is not a Utopian fantasy but a practical alternative to urban sprawl.

Speck implies that every urban dweller has a civic duty to take stock of how his city is built. We all need to be city planners, whether as hobbyists and amateurs, or as city councilmen and women.

This is especially true in the Lowcountry, where the peerless historic buildings and some of the last remaining coastal wilderness in the country need protecting. Whether you are walking on King Street in downtown Charleston, driving through rural Johns Island or commuting on U.S. Highway 17 in Mount Pleasant, you should take note of what is being built, for what reasons, and with what results.

How we get from one place to another affects our health and mental well-being, our income and enjoyment of life. It stands to reason that we should play a role in issues of such significance.

A good way to start is to read “Walkable City.”

Reviewer Carlin Rosengarten is a writer in Charleston.