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Level of autonomy in self driving cars and what they mean

Level of autonomy in self driving cars
Level of autonomy in self driving cars

As self-driving vehicles move from science fiction to reality, automakers are poised to make critical advancements in this area over the next decade. However, consumers are confused about what constitutes self-driving vehicle technology and what does not.

To set agreed-upon standards early in the transition to autonomous vehicles, the Society of Automotive Engineers (SAE) developed a classification system that defines the degree of driving automation a car and its equipment may offer. Ranging from levels zero to five, the driving automation spectrum begins with vehicles without this technology and ends with entirely self-driving vehicles.

Briefly, if a vehicle has Level 0, Level 1, or Level 2 driver support systems, an active and engaged driver is required. He/she is always responsible for the vehicle’s operation, must supervise the technology at all times, and must take complete control of the vehicle when necessary. If a vehicle has Level 3, Level 4, or Level 5 automated driving systems, the technology takes complete control of the driving with / without human supervision. With Level 3, if the vehicle alerts the driver and requests the driver to take control of the vehicle, he/she must be prepared to do so.

As of now, no vehicles sold in the market have a Level 3, Level 4, or Level 5 automated driving system. But there are several tests going on for level 3 and even level 4 autonomous vehicles.

Let's understand what are the different level of autonomy-

Level 0 (No Automation)

  • Level 0 (zero) refers to a vehicle that has no driving automation technology. In this case, the driver is entirely in charge of operating the vehicle’s movement, including steering, accelerating, braking, parking, and any other necessary maneuver to move the car in any direction.
  • However, at Level 0, driver support systems that may temporarily intervene during driving may be present. Examples include stability control, forward-collision warning, automatic emergency braking, blind-spot warning, and lane-keeping assistance. These technologies are considered Level 0 because they do not drive the vehicle but offer alerts or momentary action in specific situations.
  • The majority of vehicles we see on roadways are Level 0.

Level 1 (Driver Assistance)

  • At Level 1, the lowest level of automation, a vehicle has at least one driver support system that provides steering assistance or braking & acceleration assistance. The driver remains responsible for driving the vehicle and must be prepared to take control at any time and for any reason.
  • Adaptive cruise control is an example of a Level 1 driver assistance technology. It maintains a safe following distance between your vehicle and traffic ahead without any intervention by the driver. A steering assistance feature, such as lane-centering assistance or lane-following assistance, would also qualify as Level 1 autonomy. However, a vehicle with both of these features working together qualifies as Level 2 driving automation.
  • Cars like MG Gloster and Mahindra XUV 700 having Adaptive Cruise Control are examples of Level 1 Automation Cars.
Levels of Driving Automation
Levels of Driving Automation

Level 2 (Partial Driving Automation)

  • Level 2 driving automation applies to vehicles with advanced driving assistance systems (ADAS) that can take over steering, acceleration, and braking in specific scenarios. But, even though Level 2 driver support can control these primary driving tasks, the driver must remain alert, engaged, be ready to take control at any time and is required to actively supervise the technology at all times.
  • An example of Level 2 driving automation is Highway Driving Assist, installed in Genesis, Hyundai, and Kia vehicles. It requires the driver to have their hands on the steering wheel but actively steers, accelerates, and brakes the vehicle when traveling on highways.
  • BlueCruise is a new hands-free partial driving automation technology from Ford. It is more sophisticated than Highway Driving Assist, allowing the drivers to take their hands off of the steering wheel on specific, approved highways in the U.S. and Canada.
  • Tesla’s new Full Self Driving Capability technology (Tesla's Autopilot), GM's Super Cruise, and Nissan's ProPilot are also examples of Level 2 autonomous driving systems.

Level 3 (Conditional Driving Automation)

  • The leap from Level 2 to Level 3 automation is significant. No Level 3 systems are legal to use on American roads yet. However testing for several level 3 autonomous vehicles is ongoing.
  • Level 3 uses various driver assistance systems and artificial intelligence to make decisions based on changing driving situations around the vehicle. People inside the vehicle do not need to supervise the technology. However, a human driver must be present, alert and able to take control of the vehicle at any time, especially in the case of an emergency due to system failure. You still cannot take a nap while sitting in the driver’s seat of a Level 3 conditionally autonomous vehicle.
  • Audi developed a Level 3 traffic jam assistance technology for its 2019 A8 flagship sedan, which combines a lidar scanner with advanced sensor fusion and processing power (plus built-in redundancies should a component fail). However, while Audi was developing their marvel of engineering, the regulatory process in the U.S. shifted from federal guidance to state-by-state mandates for autonomous vehicles. So for the time being, the A8 is still classified as a Level 2 vehicle in the United States and will ship without key hardware and software required to achieve Level 3 functionality. That opened the door for Honda to become the first automaker in the world to sell an approved Level 3 traffic jam assistance system to consumers. It went on sale as an upgrade to the company’s Legend flagship sedan in early 2021, offered in low quantities and only for use in the automaker’s home market of Japan.
  • Other vehicles equipped with Level 3 driving automation but waiting for regulatory approval include the redesigned 2021 Mercedes-Benz S-Class and the all-new 2022 Mercedes-Benz EQS electric vehicle. The Mercedes technology is called Drive Pilot.
Automation Levels of Autonomous Cars
Automation Levels of Autonomous Cars

Level 4 (High Driving Automation)

  • Referred to as high-driving automation, Level 4 autonomy does not require any human interaction in the vehicle’s operation because it is programmed to stop itself in the event of system failure.
  • Level 4 driving automation technology is mostly being used in driverless taxis and public transportation services. Such vehicles will be programmed to travel between Point A and Point B and restricted to specific geographic boundaries (usually an urban environment where top speeds reach an average of 30mph). This is known as geofencing. Certain conditions may limit or cancel Level 4 autonomous vehicle operation, such as severe weather.
  • Examples of level 4 autonomous systems:-

1.  NAVYA, a French company, is already building and selling Level 4 shuttles and cabs in the U.S. that run fully on electric power and can reach a top speed of 55 mph.

2.   Alphabet's Waymo recently unveiled a Level 4 self-driving taxi service in Arizona, where they had been testing driverless cars without a safety driver in the seat for more than a year and over 10 million miles.

3.   Canadian automotive supplier Magna has developed technology (MAX4) to enable Level 4 capabilities in both urban and highway environments. They are working with Lyft to supply high-tech kits that turn vehicles into self-driving cars.

4.  Volvo and Baidu has announced a strategic partnership to jointly develop Level 4 electric vehicles that will serve the robotaxi market in China.

Level 5 (Full Driving Automation)

  • As the highest classification of driving automation, Level 5 means a vehicle can drive itself everywhere in all conditions without any human interaction. The “dynamic driving task” is eliminated. Since a human driver is never needed, a Level 4 vehicle may not have a steering wheel and pedals. And yes, at Level 4, you can take a nap while riding in the vehicle. A Level 5 vehicle is neither bound by geofencing nor affected by weather and transports human beings comfortably and efficiently without requiring a driver. They will be able to go anywhere and do anything that an experienced human driver can do. The only human involvement will be to set a destination.
  • Fully autonomous cars are undergoing testing in several pockets of the world but there are currently no public examples of level 5 autonomous vehicles.
SAE Automation Levels
SAE Automation Levels


  • While the future of autonomous vehicles is promising and exciting, mainstream production in the U.S. is still a few years away for anything higher than Level 2. Not because of technological capability, but because of the lack of security.
  • “Connected” vehicles (like autonomous cars) are rich in physical safety features like seat belts, airbags, anti lock brakes but not so rich in digital security features. When it comes to what’s needed for safe operation in a real world scenarios, connected cars are not yet ready for prime time.
  • It’s fair to say that consumers won’t accept autonomous cars unless they are confident that they will be at least as safe as they would be on a commercial jet, train, or bus. That day is coming. But the automotive industry must get over a few speedbumps first.
  • At the same time, it is very important to acknowledge that there are some loopholes and confusions in the levels of automation SAE has defined. Some of them are discussed by Steve Baker here :