IF YOU THINK the only purpose of intersections is to move cars past each other, you solve problems like a plumber: with bigger pipes. But wide, barren streets full of traffic don’t make a livable city. One solution would be nothing. No lights, no curbs, no sidewalks—just colored pavers. It works. Accidents decline, traffic slows, and property values rise. “You’ll never do as good a job as two people using body language and eye contact,” says Sam Goater, a senior associate at the Project for Public Spaces. But don’t rip out the infrastructure just yet. Urban designers have a good set of tricks to turn a city intersection into something more like a plaza and less like a freeway interchange. Cars pass, people walk, bikers bike, and everyone’s lives flow more smoothly.