Robot cars are now officially a real business. Waymo on Wednesday launched a commercial robot ride-hailing service in Arizona called Waymo One.As with Uber or Lyft, customers will summon a ride with a smartphone app. But in this case, the car will be driving itself.“This is a game changer. It’s historical in nature,” said Grayson Brulte, who heads driverless car consulting business Brulte and Co.Only “a few hundred customers” will have access to the app and participate in the early stages, according to Waymo, which is an arm of Google parent Alphabet Inc.