Jeff Speck and Chris Dempsey on what the U.S. can learn from Boston's built environment

Jeff Speck, noted urban planner and author of the book "Walkable City," and Chris Dempsey, former Massachusetts assistant secretary of transportation, are teaming up as partners at the new design firm Speck Dempsey. The pair join Radio Boston to discuss their plan to make communities more healthy, happy and walkable, with Boston as an object lesson.