Walkable cities are marvelous creations. They give us freedom from cars, freedom from sprawl, and freedom to walk our cities, as urban planner Jeff Speck says. Speck gave a TED Talk where he explained four planning principles to transform sprawling cities “into safe, walkable oases full of bike lanes and tree-lined streets.” His main point is that if you want to have a walkable city you can’t start with the sprawl model, you need the bones of an urban model and then build on it (runtime 18:37).