Self-driving cars, once the stuff of science fiction movies, are set to become a reality soon. Already many driver-assist features, such as lane changing, traffic jam assistant and others, are being offered by automakers. Such features are, essentially, stepping stones to autonomous driving technology.

By definition, an autonomous vehicle is a car that is able to take on the primary transportation capabilities of a driver-controlled car. It is able to sense its surrounding environment and navigate that space without the involvement of humans. Technology like radar, lidar, GPS and computer vision help the cars accomplish this feat.

Nearly all automakers are now in various stages of developing self-driving cars. Some have even started testing them on public roads. Although bringing these cars to market will take years, it is obvious that driverless cars have a place in the future of the auto industry. Thus, long-term investors interested in the auto sector would be well-advised to invest in stocks that look set to gain from this trend.

Here are some of the largest companies that are sure to be part of the driverless car revolution:

Alphabet Inc. (GOOGL – Analyst Report), though not an automobile company, has been the most open about the development of its self-driving car. The tech giant seems to be several paces ahead of automakers when it comes to autonomous vehicle development. Its self-driving cars are already being tested on public roads in California and Texas. Alphabet Inc. has been working on self-driving vehicles since 2010 and plans to introduce these to the public by 2020.

Tesla Motors, Inc. (TSLA – Analyst Report) is another company that is quite candid about the development of its self-driving car, which is expected to take around 5–6 years. Meanwhile, the company is set to roll out its Autopilot system this week. This will allow Tesla’s cars to be partly self-driven. The Autopilot system will enable the car to drive autonomously at highway speed as well as park itself on private property. It will also add side collision warning and improved traffic aware cruise control.