Jeff Speck, FAICP, is a city planner and the author of Walkable City, How Downtown Can Save America, One Step at a Time. It has just been reissued in an updated 10th-anniversary edition.

With Andres Duany and Elizabeth Plater-Zyberk, Mr. Speck is the co-author of Suburban Nation, which the Wall Street Journal calls “the urbanist’s bible.” His 2012 book, Walkable City–which ...