You don’t look for the essence of a city in its monuments or its museums. You look for it in its streets, where the covenant at the core of urban life—the sharing of space—plays out. For the past century, the personal car has dominated that arena, shaping the streets and environments around it. Roads are straight and wide for faster travel; intersections are regulated to protect distracted humans; businesses are located near open spaces for better parking. But as cars start to drive themselves, we have some ideas for how urban planners of the future might reimagine those outdated layouts—and transform the city into a joyful mess of throughways and byways optimized not for cars but for people.

Major Arteries

While main thorough­fares will still exist (so self-driving buses and trams can quickly get people where they need to go), there won’t need to be as many. Autonomous tech will never be perfect, but limiting the places where cars can go fast should mitigate crashes.

Green Space

Even little bits of green—a tree here, a parklet there—can improve mental health. Great news: With less space needed for everybody’s personal cars, nature can be everywhere. Also, why not move water runoff above ground as streams, for pedestrians to enjoy?