Driving the Future – Levels of Autonomous Vehicles Explained

Autonomous driving is transforming mobility, making roads safer and transportation smarter. The SAE J3016 framework defines 6 levels of automation, from driver-assist features to full self-driving capability. This guide explores each level, its key features and the road ahead for autonomous vehicles

Road safety is a shared responsibility amongst everyone working within the automotive industry. From vehicle manufacturers and technology developers to policymakers, each stakeholder plays a crucial role in reducing accidents and making roads safer for all.

The Society of Automotive Engineers (SAE), a professional association with over 128,000 engineers and technical experts in mobility engineering, together with the International Organization for Standardization (ISO TC204/WG14), have developed a framework for vehicle automation, known as SAE J3016, which has been adopted by automakers globally. This framework defines six levels of automation for cars, ranging from level 0 (No Driving Automation) to level 5 (Full Automation), which transitions from "driver assistance features" to "automated driving features".

As the journey toward full autonomy continues, understanding these levels helps contextualize the technological, legal and societal shifts that come with self-driving vehicles. We take a deep-dive into the levels of automated driving and give examples of the unique characteristics of each type of autonomy.

Levels of Automation

Level 0
No Automation

The driver is in full control of the vehicle. Vehicle features are limited to providing warnings and momentary assistance, such as anti-skid braking, blind spot warning or lane departure warnings.

Level 1
Driver Assistance

The driver is in control of the vehicle. Vehicle assistance features can provide independent steering OR break/acceleration support to the driver, such as lane centering OR adaptive cruise control.

Level 2
Partial Automation

The driver is in control of the vehicle. Partial driving automation provides steering AND break/acceleration to support the driver, such as lane centering AND adaptive cruise control at the same time.

Level 3
Conditional Automation

When conditional driving automation is enabled, the driver isn't controlling the vehicle but must be ready to take over when the system requests. This automation operates under limited conditions, like in slow moving traffic jams.

Level 4
High Automation

The driver is not required to control the vehicle, and therefore pedals or steering wheels may or may not be installed. The high driving automation will fully control the vehicle under certain conditions, such as geo-fenced areas.

Level 5
Full Automation

This feature does not require the driver to take control at all. The vehicles has complete autonomy under all conditions and are capable of navigating any road or environment without human input.

Key Characteristics of Driving Automation

Level 0 – No Driving Automation

Level 0 autonomous driving refers to a vehicle with no driving automation. At this level, the human driver is fully responsible for controlling the vehicle at all times, but the car may have limited driver assistance features such as warnings or momentary intervention features that do not have sustained automation. For example, a car with automatic emergency braking may momentarily intervene to prevent a crash, but since the driver is still required to manage all other driving tasks, it remains a Level 0 vehicle.

Key Characteristics of SAE Level 0:

• No sustained automation: The driver must perform all driving tasks, including steering, braking, acceleration and monitoring the environment.

• Warnings and alerts: The driver must always be alert, but the vehicle can have warnings to assist the driver, such as

  • Forward collision warnings

  • Lane departure warnings

  • Blind-spot warnings

• Limited driver assistance features – Some vehicles at level 0 may have momentary intervention systems, such as:

  • Automatic Emergency Braking (AEB)

  • Adaptive Cruise Control (ACC) if it provides momentary intervention

Level 1 – Driver Assistance

Level 1 autonomous driving refers to a vehicle that has a single automated driving feature that assists either steering or acceleration/braking, but not both simultaneously (a car with both cruise control and lane keeping that operate simultaneously would be considered Level 2, since two functions, steering + speed control, are working together). The human driver is still required to remain fully engaged and responsible for monitoring the environment in level 1 vehicles.

Key Characteristics of SAE Level 1:

• Single automated function – Either steering assistance (e.g., lane-keeping assist) or acceleration/braking assistance (e.g., adaptive cruise control), but not both together.

• Driver must remain in control – The system does not replace the driver but can support them. The driver must be ready to take full control at any time.

• No full automation – The driver is responsible for monitoring the driving environment and handling complex driving decisions.

Level 2 – Partial Automation

Level 2 autonomous driving refers to a vehicle that can simultaneously control both steering and acceleration/braking under certain conditions, such as in slow moving highway traffic. A car with Level 2 automation is still not self-driving— The human driver must remain fully ready to take over immediately if needed.

Key Characteristics of SAE Level 2:

• Simultaneous automation of steering and acceleration/braking – Unlike Level 1, which only automates one function at a time, level 2 can handle both at the same time.

• Driver supervision required – The system does not monitor the environment; the human driver must stay engaged and be ready to intervene.

• Limited operational conditions – Level 2 systems typically work only on well-marked highways or specific road conditions, this could include

  • Advanced Adaptive Cruise Control with Lane Centering – The car automatically adjusts speed and maintains lane position, but the driver must stay alert.

  • Tesla Autopilot (Basic Version) – Helps steer, accelerate, and brake on highways but requires hands on the wheel.

  • Chevrolet Super Cruise (Hands-Free, but Eyes-On System) – Allows hands-free driving in certain mapped areas but requires driver attention.

Level 3 – Conditional Driving Automation

Level 3 autonomous driving introduces the first stage where the vehicle can perform all driving tasks under specific conditions, without requiring constant driver supervision. However, the driver must be available to take over when the system requests it. Unlike level 2, level 3 allows the driver to disengage from active monitoring, but the system is not yet fully autonomous since it still requires a fallback-ready human driver.

Key Characteristics of SAE Level 3:

• Automated driving in certain conditions – The vehicle can fully control steering, acceleration, braking, and make driving decisions within its Operational Design Domain (ODD), such as on highways or in traffic jams.

  • Honda Sensing Elite – Features a "Traffic Jam Pilot" that takes full control in stop-and-go highway traffic.

  • Mercedes-Benz Drive Pilot – Allows hands-off driving in heavy traffic at speeds up to 40 mph (65 km/h) on mapped highways.

• No continuous driver supervision required – Unlike level 2, the driver can divert attention from the road (e.g., watch a video or read) but must be ready to take control when prompted.

• System requests driver intervention when needed – If conditions go beyond its capabilities (e.g., bad weather, construction zones), the system will notify the driver to take over.

Level 4 – High Driving Automation

According to the SAE J3016 standard, Level 4 autonomous driving means the vehicle can perform all driving tasks within a defined operational domain (e.g., specific roads, cities, or weather conditions) without requiring human intervention. If the system encounters a situation it cannot handle, it does not require a driver to take over—it will safely stop or reroute on its own, and therefore these vehicles may or may not have a steering wheel or pedals.

Key Characteristics of SAE Level 4:

• No human intervention required – The driver is not needed as a fallback, meaning the vehicle can handle emergency situations and system failures independently.

• Full automation in specific urban areas – The vehicle can operate without human input, but only in pre-defined conditions, such as mapped urban areas or dedicated self-driving zones

  • Waymo fully self-driving taxis operate in designated areas of Phoenix, Las Angeles and San Francisco, requiring no driver inside.

• Geofenced operation – Level 4 vehicles are limited to certain locations or conditions, such as city streets with good infrastructure.

  • Navya self-driving shuttle buses operated within the geofenced areas like university campuses and airports •

• May or may not have manual controls – Some level 4 vehicles opt to remove the steering wheel and pedals. o

  • Xoox robotaxis, which operate in a geofenced area in Las Vegas (including the strip and surrounding areas), have no driver, steering wheel, or pedals

Level 5 – Full Driving Automation

While Level 5 remains a long-term goal, advancements in AI and sensor technology are driving progress towards fully automated vehicles. This is the highest level of autonomous driving according to the SAE, meaning the vehicle is fully self-driving in all conditions, with no human intervention required at any time. Unlike level 4, which operates only in specific environments, level 5 vehicles can function anywhere a human driver could—on highways, city streets, rural roads and in all weather conditions.

Key Characteristics of SAE Level 5:

• No driver needed – The vehicle operates without any human input, under all conditions, anywhere.

• No steering wheel or pedals required – Since human control is unnecessary, level 5 vehicles may be designed without traditional driving controls.

• Works in all environments – Unlike Level 4, which is geofenced, Level 5 vehicles can drive on any road and in any traffic condition.

• No fallback to a human driver – The system must be capable of handling all driving situations, including emergencies.

Level 5 autonomy is not yet available commercially, however some companies have made impressive progress with level 5 concept vehicles, such as:

• Audi AI:CON - Encapsulates a concept of fully autonomous mobility, the Audi AI:CON has created a ‘third living space’ where the car is capable of interacting not only with its surroundings, but also its occupants. For example, the vehicle can suggest ordering food from the occupant's favorite restaurant before driving itself there for food collection.

• Volvo 360c - A futuristic sleeping pod on wheels that envisions a world where people use self-driving cars instead of airplanes for short-distance travel.

• Volkswagen Sedric - designed, developed, and constructed by Volkswagen Group's Future Center, Sedric is fitted with two comfy sofa-style seats that face each other, and was designed to drive children to school, drop their parents at the office, and then look independently for a parking space.

Want to learn more about how Neonode's Hands-on-wheel detection can assist with level 2 and level 3 autonomous driving?