Zoox on Tuesday began allowing select San Francisco users to hail its driverless vehicles, pitting the Amazon -owned robotaxi service against Alphabet's Waymo in the same market for the first time. Riders can sign up to join the "Zoox Explorers" program to take free rides in the company's box-shaped vehicles in certain San Francisco neighborhoods, including SoMa and the Mission and Design districts, the company said. Zoox will take users off the waitlist depending on their location and as it