New details regarding Apple’s efforts in autonomous car technology were revealed in a patent published this week, spotted by Autoblog.

The patent, called "Autonomous Navigation System," was filed by Apple in 2015, about a year after the company reportedly started working on self-driving technology.

The paperwork filed with the U.S. Patent and Trademark Office details a navigation system with sensors installed in the vehicle that provides “updates to a virtual characterization” of a route drivers have traveled on. The patent also mentions a “ database of characterizations,” where information on traveled roads can be stored in.

The patent says :

“Some embodiments provide an autonomous navigation system which enables autonomous navigation of a vehicle along one or more portions of a driving route based on monitoring, at the vehicle, various features of the route as the vehicle is manually navigated along the route to develop a characterization of the route.”

The data would allow the self-driving vehicle to eliminate the need of repeatedly remaking detailed maps.

“The characterization is progressively updated with repeated manual navigations along the route, and autonomous navigation of the route is enabled when a confidence indicator of the characterization meets a threshold indication,” the patent says.

The continuous updates to the routes’ characterizations include data from when human drivers are on the wheel, when conditions change, like road construction and lane closures, as well weather events.

The patent is just an idea, and doesn’t mean Apple will actually pursue it. However, it does show the company’s efforts in autonomous technology and what it’s interested in.

Apple’s autonomous car project, dubbed Project Titan, has been kept away from the spotlight. The company rarely reveals details about its self-driving technology. However, Apple CEO Tim Cook did provide some information about Project Titan in June. Cook clarified that the company was not looking to build its own self-driving car, but was instead focusing on an autonomous car system.

A couple of months ago, a video was uploaded on Twitter which seemed to show Project Titan’s test Lexus SUV. The footage shows a white SUV equipped with 6 LiDARS on the top of the vehicle. Photos revealed in April also showed the Lexus.

Last month, Apple released a research paper online detailing developments in its autonomous technology efforts. In the paper, researchers proposed a new software approach called VoxelNet, which would help computers detect 3D objects. VoxelNet is described as “a novel end-to-end trainable deep architecture for point cloud based 3D detection” and said it “achieves highly encouraging results in detecting pedestrians and cyclists from LiDAR point cloud.”