When Uber and Lyft first emerged, the companies said they would reduce traffic, with the idea being that people would ditch their cars and use an Uber or Lyft instead, including by people sharing rides to get to work.

But, the Wall Street Journal reports the opposite is true, and the ride-hailing companies have instead made traffic worse in U.S. cities and in cities outside the U.S., and it’s led places like New York, Chicago and San Francisco to impose new fees on them. It turns out most riders aren’t sharing their Ubers or Lyfts but are riding alone, and people are now less likely to use public transportation in favor of a ride.