Paris

On Sunday, streets all over Paris belonged to people biking, walking, and riding transit.

In Europe it's common for regional rail systems to get ridership comparable to that of the subway in the central city. But in America, this is unheard of. One reason for the discrepancy is land use: American commuter rail stations are typically surrounded by parking, while in the Paris region you see a different pattern with ample development next to suburban train stations.

In the U.S., regional rail is mostly good for one type of trip: the commute. But in Paris, regional rail is oriented toward all types of trips, and people ride throughout the day, not just at rush hour. One key to success is running frequent, predictable service all day long.

After years of experimentation, the Paris City Council this week committed to the permanent conversion of two miles of the Georges Pompidou expressway along the River Seine into a waterfront park.

If you look at paintings from the pre-automotive era, Paris's monumental public squares were full of people strolling comfortably. But over time, car traffic has consumed most of these squares.

After a decade of repurposing street space from cars to people, buses, and bikes, Paris isn't done yet. The world's most-visited city is now preparing to remove even more traffic from the streets in the name of walkability and clean air.

People riding shared public bicycles appear to be involved in fewer traffic crashes and receive fewer injuries than people riding their personal bicycles. In cities from Paris and London to Washington, D.C. and Mexico City, something about riding a shared bicycle appears to make cycling safer.

Flashback to Europe, sixty years ago. Just emerging from the ruin of total war, the continent was in the midst of a nearly unprecedented reconstruction. Over the next decade, industry finally was able to turn toward consumer products, from stockings to refrigerators and, of course, the automobile. Italians owned only 342,000 cars in 1950, but ten years later that number had increased to two million, according to historian Tony Judt. In France, the number of cars tripled over the decade.