SAN FRANCISCO (AP) — Google is preparing to expand a San Francisco carpooling program in a move that could that could set up a showdown with its one-time ally, the popular ride-hailing service Uber. The plans will build upon a test service that Google's navigation app Waze launched three months ago in the San Francisco Bay Area. The program allows anyone using the Waze app to offer a ride to a limited pool of people trying to get to work or home. Now, only people working at six companies, including Google, Wal-Mart Stores and Adobe Systems, can request rides.Read more on NewsOK.com