Several minivans with camera equipment strapped to the top have been spotted driving around San Francisco. The vehicles have been confirmed as belonging to Apple, although nobody is sure what they are doing by driving around with all those sensors.
The minivans appear to have a camera rig that captures images all around the vehicle. It is speculated that Apple is preparing a feature similar to Google Street View for Apple Maps. Having images of streets would go a long way to improving the quality of Apple Maps, which has struggled against other navigation services like Google Maps and Waze (although those two are arguable the same thing now).
Adding fuel to the mapping theory is the fact that the cars are also fitted with spinning sensors that could be LiDAR, which uses light to measure distance. LiDAR is most often used to make high-resolution maps, and would definitely be employed if Apple was in the middle of a top secret mapping project.
That being said, at least one analyst thinks that the camera setup resembles a driverless car arrangement. Which is highly unlikely as Apple does not have any permits that would allow them to put those cars on the road.