It's integral to a certain class of self-driving cars. Waymo relies on centimeter-level mapping of the environment, and sure, could not possibly operate without a map. The car establishes its exact environment in the world using the maps, and I presume then looks for things then in that environment to track.

Comma.ai, on the other hand, feeds their AI the camera feed and the sensor signals from the car, and it responds, as far as I know, almost entirely based on that stimulus. Of course, Comma.ai's car is presumably less predictable, it relies on a black box to "think", but you could feed it the general concept of what path to take from A to B, even a set of waypoint GPS coordinates of where to turn, and hypothetically, such a car could navigate to that destination otherwise offline, or with the grade of maps reasonably available offline. It's intended to drive like a human drives: Based on the information it perceives in the world around it.