Self-driving cars present a whole new world of technology. As companies continue to develop and implement automated car technology, vehicles have emerged with widely varying ranges of automation. The National Highway Traffic Safety Administration (NHTSA) has established a tiered system for classifying cars based on their levels of automation and human involvement.
A Level 0 car contains no automation. This is a traditional car in which the driver is in charge of all car functions at all times.
Level 1, referred to as “function specific automation,” means the car has some automation of one or more specific functions. This could be a feature like electronic stability control, or a braking automation that allows the car to stop faster than it would if the driver were in sole control.
Level 2, referred to as “combined function automation,” means that the car has “at least two primary control functions designed to work in unison to relieve the driver of control of those functions.” An increasingly common Level 2 function is adaptive cruise control, which controls both speed and lane centering. Another Level 2 function includes self-parking cars, which controls for speed and steering. Several car manufacturers have Level 2 cars on the road today, and even more models are slated to come out with technology that falls under Level 2.
Level 3, referred to as “limited self-driving automation,” means the driver can “cede full control of all functions under certain traffic or environmental conditions and in those conditions [can] rely heavily on the vehicle to monitor for changes in those conditions, requiring transition back to driver control.” In a Level 3 car, the driver must be available and able to take control, but the car would classify as what most people consider self-driving. The cars that Google is currently testing are fully automated, but have a steering wheel and brake/gas pedal so a driver can take control, and so they are considered Level 3 vehicles.
Level 4, the highest level, is known as “full self-driving automation.” A Level 4 car “is designed to perform all safety-critical driving functions and monitor road conditions for an entire trip.” A Level 4 car does not require a qualified driver to be in the vehicle. In fact, a Level 4 car can operate completely unoccupied. A “driver” must input a destination, but that “driver” need not be able to actually operate the vehicle.
To read more about the NHTSA levels of automation, visit http://www.nhtsa.gov/About+NHTSA/Press+Releases/U.S.+Department+of+Transportation+Releases+Policy+on+Automated+Vehicle+Development.