"While Uber has steadily expanded to more cities across the US, we expect demand for transportation-oriented sharing economy services, like Uber, to reach a cap," said eMarketer forecasting analyst Oscar Orozco in a statement. The firm predicts 15 million U.S. adults will use ride-sharing services in 2016, and 17 million in 2017. The numbers reflect growth in usership of 20.5 percent and 13.3 percent, respectively. Users grew by more than 50 percent in 2014 and 2015, so growth has already slowed. By 2018, eMarketer predicts the number of riders will increase by only 7.2 percent. Why the projected slowdown? Orozco points out a few factors: - Continued competition from traditional taxi services - Regulations and government bans - Saturation among business travelers, a group that has driven growth Get the full story at Inc.com Read also "Will Airbnb Be the Shared Economy’s MySpace?" at Hospiality.Net and "Uber Bummed: How Uber and Lyft Lost an Important Political Fight" at Entrepreneur