Okay, but Uber literally cannot put enough cars into the city to move five million people around every day, and they're sure as shit not going to dig their own tunnels.
They raised just North of a billion dollars [0] in September, the 2nd Ave Subway is expected to cost $4.5b [1] for 1.5m of track, three new stops, and a new entrance at an old stop. So yea, you can be sure as shit they're not building their own tunnels. At least not here.
[0] - https://www.crunchbase.com/organization/uber/funding-rounds [1] - http://money.cnn.com/2012/05/31/news/economy/nyc-subway-cons...