San Francisco, London – In documents submitted to California regulators earlier this month, Apple Inc outlined a plan to train operators of self-driving cars, the latest step emphasizing the company’s ambitions concerning autonomous vehicle technology.

Apple acquired a permit to test self-driving cars on April 14 from the California Department of Motor Vehicles, but the company has never said anything about its plan.

The state allowed Reuters to acquire 41 pages of Apple application documents that shed some light on the company’s highly secret self-driving effort, which it has never officially acknowledged.

Apple joins a long list of carmakers, start-ups and technology rivals, including Alphabet’s Waymo (Google’s mother-company) that are testing cars on California’s roads.

Apple is looking for new hit products and autonomous car technology is expected to revolutionize the traditional auto industry. The application submitted by Apple included a 10-page training plan that appeared to be related to operators who will manually drive the car during automated driving exercises of the system, which it calls a development platform. Apple refused to give any additional information on the issue.

The document does not include detail on how Apple’s self-driving platform actually works or other technical details. It also does not say what kind of sensors are found on Apple’s three permitted vehicles, all 2015 Lexus model RX450h. The permit does not necessarily mean that Apple itself is building a full car. It could instead be designing a self-driving platform that can be integrated into other manufacturer’s cars.