They're more than just prototypes. Their employees are using self-driving cars for their daily lives. If you have a friend who works at Google (well Waymo now) who is using the car, you can get a ride. Also, as a driver on Mt View roads, I have experience self-driving as someone behind and next to the vehicle. They aren't the "robotic" drivers you'd expect, but fit in pretty well. They still show signs of being a robot (like the way they approach a turn with a biker is very mechanical) so you can tell it is self driving, but it clearly works.

And also there is Uber's self driving fleet. They are actually taking people from place to place who use the Uber app in a self driving vehicle.

In all cases someone is still at the wheel, but they aren't doing anything other than monitoring and logging the ride and cases where the car didn't behave like a "normal" driver.