What is an autonomous vehicle? Definition and meaning

An autonomous vehicle, also known as a driverless vehicle, is a vehicle that can move and guide itself without human input. 

Autonomous vehicles are able to perceive their surroundings and travel to different locations through a combination of sensors, cameras, radar and artificial intelligence (AI). Advanced control systems can interpret sensory information to detect obstacles and choose the most appropriate navigation path for the vehicle.

The basic stages of autonomous driving break down into: partially automated, highly automated and fully automated.

  • Partially automated – requires a human driver to continuously monitor the automatic functions. The driver cannot perform any non-driving tasks.
  • Highly automated – the vehicle’s automatic system is aware of its limitations and calls for the driver to take control when necessary. The human driver can perform some non-driving tasks depending on the circumstance.
  • Fully automated – the vehicle’s automated system can handle all situations autonomously and there is no need for a human driver.

The US National Highway Traffic Safety Administration (NHTSA) believes that “self-driving vehicles ultimately will integrate onto U.S. roadways by progressing through six levels of driver assistance technology advancements in the coming years.”

Waymo_Pacifica
A fully autonomous Waymo Chrysler Pacifica hybrid-minivan. Waymo, a subsidiary of Alphabet, is one many self-driving technology development companies testing autonomous vehicles. As of 2018, Waymo had tested its system in six states and 25 cities across the US.

The six different levels of automation

The SAE’s automation classification system is based on six different levels (from zero automation to full automation). The SAE J3016 is the U.S. Dept. of Transportation’s official reference for defining levels of vehicle autonomy.

  • Level 0 – There is no autonomy and the human driver does all the driving.
  • Level 1 – The vehicle is controlled by the driver, but some assist features may be included. The advanced driver system (ADS) on the vehicle can “sometimes assist” the human driver.
  • Level 2 – The vehicle has combined automated functions, but the human driver must remain engaged with the driving task and monitor the driving environment at all times.
  • Level 3 – The ADS on the vehicle can perform aspects of the driving task simultaneously under some circumstances. The human driver must be ready to take control at all times with notice.
  • Level 4 – The ADS on the vehicle can perform all driving tasks in certain circumstances or only in limited spatial areas. During those circumstances the human driver does not need to pay attention. 
  • Level 5 – No human intervention is necessary. At this level human occupants are passengers. An ADS on the vehicle is capable of doing all driving tasks in all circumstances.

It should be noted that there is inconsistency in what constitutes an “autonomous” or “driverless” vehicle in the automotive industry. According to SAE International’s J3016 standard: “Some vernacular usages associate autonomous specifically with full driving automation (level 5), while other usages apply it to all levels of driving automation, and some state legislation has defined it to correspond approximately to any ADS at or above level 3 (or to any vehicle equipped with such an ADS).”


A short but informative 2 minute long animated video created by the International Automobile Federation on autonomous vehicles:


Pros and cons of autonomous vehicles

Potential benefits of autonomous vehicles include:

  • Increased safety – approximately 1.2 million people die in traffic accidents every year. The widespread adoption of autonomous vehicles could reduce the number of auto incidents.
  • Better mobility and less traffic – autonomous cars can communicate with one and another and identify the most optimal route which could reduce congestion and make transport by car more seamless.
  • Reduced emissions
  • Reduced costs

Potential cons:

  • They are more vulnerable to hackers and other cyber threats.
  • Some people’s jobs could be made obsolete.

Legal definition

In the District of Columbia (DC) code,

“”Autonomous vehicle” means a vehicle capable of navigating District roadways and interpreting traffic-control devices without a driver actively operating any of the vehicle’s control systems. The term “autonomous vehicle” excludes a motor vehicle enabled with active safety systems or driver- assistance systems, including systems to provide electronic blind-spot assistance, crash avoidance, emergency braking, parking assistance, adaptive cruise control, lane-keep assistance, lane-departure warning, or traffic-jam and queuing assistance, unless the system alone or in combination with other systems enables the vehicle on which the technology is installed to drive without active control or monitoring by a human operator.”