What if we were all Uber drivers?

I just had an idea. What if there existed %50 of the cars that exist in US today, but they were freely available for everyone. What's the catch? You have to pick up people on the way to where you are going. There will be a cloud system that similar to Uber, where people input where they need to go. If they see a car standing, they can just start driving it. If there's someone who needs picking up on the way, they do it. Each person will have a card they scan when the get in the car or drive it. This way you identify cheaters (those who didn't pick up appropriately). What do you think?