How Much Traffic Do Uber and Lyft Cause?

After the 2008 economic crash, Americans began driving less. But it didn’t last long: In every year since 2013, U.S. drivers have packed on more miles behind the wheel. This rise in vehicle-miles traveled (VMT, in wonk-speak) can be seen and felt in the nation’s metropolises. Congestion on major arteries like L.A.’s I-405 or San Francisco’s Geary Boulevard is getting worse; pedestrian death counts are reaching record heights; tailpipe emissions are growing thicker.

Also new since the Great Recession—Uber and Lyft. These ride-hailing services stormed into cities in the 2010s with a grand utopian promise: By tapping into America’s vast reservoir of idle vehicles, on-demand, app-based rides would reduce the need for personal car ownership and ultimately remove cars from the road.