Well, also, you've got the factor that if you can use uber to get to the places transit doesn't go, then you're more likely to go car-free. I live in ATL, and take transit to work, but if I had a car, I'd likely end up driving everywhere just because of the "well, I'm paying for a car, may as well save 5 minutes instead of paying for transit". Sure, some of the trips probably are instead of transit, but having uber as an option certainly dramatically increased how often I took transit.