Saw the Maps truck the other day. There were two of them and a pickup truck following the caravan.
These data-gathering vans began rolling out in June 2018, starting in San Francisco. They are equipped with a wheel encoder and GPS that keeps track of the vehicle’s movement and provides “ground truth” to the maps being generated, four Lidar sensors mounted on each corner provide a precise 3D scan of the road and 360-degree cameras for virtual reality street view.
Notice that this is not an autonomous vehicle, though there are rumors that the data vehicle gathers will lay the groundwork for unmanned mapping cars in the not-so-distant future.