One reason Uber and Lyft are so popular is their ubiquity. You don’t have to wait long after tapping on your app and agreeing on a price. What if, however, there was a limit to the number of Uber or Lyft cars that could ply Chicago streets? Fewer ride-share cars would mean longer wait times for pickups. And with the supply of cars restricted, demand would go up — which would likely lead to higher prices.