Apple has confirmed it is working on the technology for a self-driving vehicle.
The confirmation of one of Silicon Valley's worst-kept secrets came in a letter to the US highway authority, the National Highway Traffic Safety Administration (NHTSA).
In the letter, Apple says it is "investing heavily in the study of machine learning and automation, and is excited about the potential of automated systems in many areas, including transportation".
The NHTSA is overseeing planned regulations for self-driving vehicles.
Apple's director of product integrity Steve Kenner wrote that "under NHTSA's guidance, automated vehicles have the potential to greatly enhance the human experience - to prevent millions of car crashes and thousands of fatalities each year and to give mobility to those without it".
The Wall Street Journal first reported that Apple had sent the letter.
In the letter Apple stops short of saying it is building a self-driving car, but acknowledges it is working on technology that would be used in autonomous vehicles.
The letter argues that companies working on self-driving technology should share information about "crashes and near-misses". However Mr Kenner added that it is important that individual drivers' confidentiality be respected.
For some years Apple has reportedly been working on self-driving technology, under the name Project Titan.
Some analysts believe that rather than building its own car, Apple has decided to develop technology that could be licenced to other companies for their self-driving vehicles.
Project Titan has reportedly suffered from delays and restructuring as Apple realised the challenges of trying to design and manufacture a mass-market vehicle.
Three months ago Apple reportedly restructured the unit working on the self-driving technology, shifting its focus from building its own car to designing the operating system and software for autonomous vehicles.
In October, Bloomberg reported the self-driving technology team had been given until late next year to prove to Apple's executives that the project is viable.