The U.S. National Highway Traffic Safety Administration defines five levels of automation in vehicles.
Level 0 — No automation: “The driver is in complete and sole control of the primary vehicle controls.” The car offers no assistance at all, not even cruise control. About 10 per cent of the cars on the road are in this category.
Level 1 —Function-specific automation: “Automation at this level involves one or more specific control functions.” More than half of all cars are at this level, which would include things like cruise control and electronic stabilization systems. The systems aren’t interconnected, however.http://ottawacitizen.com/news/local-news/defining-a-self-driving-car