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The continuing evolution of automotive technology aims to deliver even greater safety benefits and automated driving systems (ADS) that — one day — can handle the whole task of driving when we don’t want to or can’t do it ourselves. Fully automated cars and trucks that drive us, instead of us driving them, will become a reality. These self-driving vehicles ultimately will integrate onto U.S. roadways by progressing through six levels of driver assistance technology advancements in the coming years.

The Topic

The Evolution of Automated Safety Technologies

Related Topic

Driver assistance technologies in today’s motor vehicles are already helping to save lives and prevent injuries.

A number of today’s new motor vehicles have technology that helps drivers avoid drifting into adjacent lanes or making unsafe lane changes, or that warns drivers of other vehicles behind them when they are backing up, or that brakes automatically if a vehicle ahead of them stops or slows suddenly, among other things. These and other safety technologies use a combination of hardware (sensors, cameras, and radar) and software to help vehicles identify certain safety risks so they can warn the driver to act to avoid a crash.

The continuing evolution of automotive technology aims to deliver even greater safety benefits and – one day – deliver automated driving systems (ADS) that can handle the whole task of driving when we don’t want to or can’t do it ourselves.

A Vision for Safety: Learn More

Download NHTSA’s voluntary guidance, technical documentation, and additional resources related to automated vehicles. Find out what’s included in AV 2.0, AV 3.0, AV 4.0 and what’s changed, and get answers to common questions.

Five Eras of Safety

1950 - 2000

Safety/Convenience Features

Cruise Control
Seat Belts
Antilock Brakes

2000 – 2010

Advanced Safety Features

Electronic Stability Control
Blind Spot Detection
Forward Collision Warning
Lane Departure Warning

2010 – 2016

Advanced Driver Assistance Features

Rearview Video Systems
Automatic Emergency Braking
Pedestrian Automatic Emergency Braking
Rear Automatic Emergency Braking
Rear Cross Traffic Alert
Lane Centering Assist

2016 - 2025

Partially Automated Safety Features

Lane keeping assist
Adaptive cruise control
Traffic jam assist


Fully Automated Safety Features

Highway autopilot

The Topic

The Road to Full Automation

Fully autonomous cars and trucks that drive us instead of us driving them will become a reality. These self-driving vehicles ultimately will integrate onto U.S. roadways by progressing through six levels of driver assistance technology advancements in the coming years. This includes everything from no automation (where a fully engaged driver is required at all times), to full autonomy (where an automated vehicle operates independently, without a human driver).

The Topic


What does this mean for you as a driver?


Levels of AutomationWho does what, when
Level 0The human driver does all the driving.
Level 1An advanced driver assistance system (ADAS) on the vehicle can sometimes assist the human driver with either steering or braking/accelerating, but not both simultaneously.
Level 2An advanced driver assistance system (ADAS) on the vehicle can itself actually control both steering and braking/accelerating simultaneously under some circumstances. The human driver must continue to pay full attention (“monitor the driving environment”) at all times and perform the rest of the driving task.
Level 3An automated driving system (ADS) on the vehicle can itself perform all aspects of the driving task under some circumstances. In those circumstances, the human driver must be ready to take back control at any time when the ADS requests the human driver to do so. In all other circumstances, the human driver performs the driving task.
Level 4An automated driving system (ADS) on the vehicle can itself perform all driving tasks and monitor the driving environment – essentially, do all the driving – in certain circumstances. The human need not pay attention in those circumstances.
Level 5An automated driving system (ADS) on the vehicle can do all the driving in all circumstances. The human occupants are just passengers and need never be involved in driving.
Plain language description of the SAE levels of automation

Benefits of Automation


The safety benefits of automated vehicles are paramount. Automated vehicles’ potential to save lives and reduce injuries is rooted in one critical and tragic fact: 94% of serious crashes are due to human error. Automated vehicles have the potential to remove human error from the crash equation, which will help protect drivers and passengers, as well as bicyclists and pedestrians. When you consider more than 35,000 people die in motor vehicle-related crashes in the United States each year, you begin to grasp the lifesaving benefits of driver assistance technologies.

Economic and Societal Benefits

Automated vehicles could deliver additional economic and additional societal benefits. A NHTSA study showed motor vehicle crashes in 2010 cost $242 billion in economic activity, including $57.6 billion in lost workplace productivity, and $594 billion due to loss of life and decreased quality of life due to injuries. Eliminating the vast majority of motor vehicle crashes could erase these costs.

Efficiency and Convenience

Roads filled with automated vehicles could also cooperate to smooth traffic flow and reduce traffic congestion. Americans spent an estimated 6.9 billion hours in traffic delays in 2014, cutting into time at work or with family, increasing fuel costs and vehicle emission. With automated vehicles, the time and money spent commuting could be put to better use. A study stated that automated vehicles could free up as much as 50 minutes each day that had previously been dedicated to driving.


While its full societal benefits are difficult to project, the transformative potential of automated vehicles and their driver assistance features can also be understood by reviewing U.S. demographics and the communities these technologies could help to support.

For example, automated vehicles may also provide new mobility options to millions more Americans. Today there are 49 million Americans over age 65 and 53 million people have some form of disability.

In many places across the country employment or independent living rests on the ability to drive. Automated vehicles could extend that kind of freedom to millions more. One study suggests that automated vehicles could create new employment opportunities for approximately 2 million people with disabilities.

The Topic

Frequently Asked Questions

Automated or “self-driving” vehicles are a future technology rather than one that you’ll find in a dealership tomorrow or in the next few years. A variety of technological hurdles have to be cleared, and other important issues must be addressed before these types of vehicles can be available for sale in the United States. The Department of Transportation is committed to supporting the innovators who are developing these types of vehicles to ensure their safe testing and deployment before they are available to consumers.

Automated vehicles and driver assisting technologies (including those already in use on the roads) have the potential to reduce crashes, prevent injuries, and save lives. Of all serious motor vehicle crashes, 94 percent are due to human error or choices. Fully automated vehicles that can see more and act faster than human drivers could greatly reduce errors, the resulting crashes, and their toll.

There is no vehicle currently available for sale that is “self-driving.” Every vehicle currently for sale in the United States requires the full attention of the driver at all times for safe operation. While an increasing number of vehicles now offer some automated safety features designed to assist the driver under specific conditions, there is no vehicle currently for sale that is fully automated or “self-driving.”

Many vehicles today include safety features that assist drivers in specific circumstances, such as keeping us from drifting out of our lane or helping us stop in time to avoid a crash or reduce its severity. Read more about on this on NHTSA's safety technologies topic. If you’re currently shopping for a new vehicle, review NHTSA’s 5-Star Safety Ratings to make informed decisions about the safety features included in your new vehicle. If you're currently shopping for a new vehicle, review NHTSA's 5-Star Safety Ratings to make informed decisions about the safety features in your new vehicle.

Vehicles are tested by the companies that build them. Companies must comply with Federal Motor Vehicle Safety Standards and certify that their vehicle is free of safety risks. Many companies today are testing advanced automated vehicles to ensure that they operate as intended, but a great deal of work remains to be done to ensure their safe operation before they are made publicly available.

Cybersecurity is a critical issue that DOT and automotive companies are working to address for the future safe deployment of these technologies. Advanced vehicle safety technologies depend on an array of electronics, sensors, and computing power. In advancing these features and exploring the potential of fully autonomous vehicles, DOT and NHTSA are focused on cybersecurity to ensure that these systems work as intended. You can read more about our approach by visiting NHTSA's vehicle cybersecurity topic.

These are among many important questions beyond the technical considerations that policymakers are working to address before automated vehicles are made available. We are still many years from fully automated vehicles becoming available to the public.

A vehicle that is fully automated will be capable of controlling all aspects of driving without human intervention, regardless of whether its design includes controls for a human driver. Companies may take different design approaches to fully “self-driving” vehicles that do or do not include controls allowing for a human driver. As is the case now, consumers will decide what types of vehicle designs best suit their needs.

A fully automated vehicle could provide new mobility options for older people and for those with disabilities. Some older Americans and people with disabilities are able to drive today by adapting or modifying their vehicles to meet their specific needs. Fully automated vehicles could offer new mobility options to many more people, helping them to live independently or to better connect them to jobs, education and training, and other opportunities.

NHTSA In Action

NHTSA is dedicated to advancing the lifesaving potential of new vehicle technologies

NHTSA demonstrates its dedication to saving lives on our nation’s roads and highways through its proactive and inclusive approach to the safe development, testing, and deployment of new and advanced vehicle technologies that have enormous potential for improving safety and mobility for all Americans, NHTSA demonstrates its dedication to saving lives on our nation’s roads and highways.

In September 2016, NHTSA and the U.S. Department of Transportation issued the Federal Automated Vehicles Policy which set forth a proactive approach to providing safety assurance and facilitating innovation. Building on that policy and incorporating feedback received through public comments, stakeholder meetings, and Congressional hearings, in September 2017, the agency issued, Automated Driving Systems: A Vision for Safety 2.0. The updated guidance, 2.0, offers a flexible, nonregulatory approach to automated vehicle technology safety, by supporting the automotive industry and other key stakeholders as they consider and design best practices for the safe testing and deployment of ADS levels 3 through 5. It also provides technical assistance to states and best practices for policymakers regarding ADS.

In October 2018, U.S. DOT released Preparing for the Future of Transportation: Automated Vehicles 3.0, which builds upon — but does not replace — the voluntary guidance provided in 2.0. AV 3.0 expands the scope to all surface on-road transportation systems, and was developed through input from a diverse set of stakeholder engagements throughout the nation. AV 3.0 is structured around three key areas:

  1. Advancing multi-modal safety,
  2. Reducing policy uncertainty, and
  3. Outlining a process for working with U.S. DOT.

Ensuring American Leadership in Automated Vehicle Technologies: Automated Vehicles 4.0 was released in January 2020. AV 4.0 builds upon AV 3.0 by expanding the scope to 38 relevant United States Government (USG) components that have direct or tangential equities in safe development and integration of AV technologies. AV 4.0 is structured around three key areas: 

  1. USG AV principles,
  2. Administration efforts supporting AV technology growth and leadership, and 
  3. USG activities and opportunities for collaboration.

As automated technologies advance, so will the department’s guidance. The guidance is intended to be flexible and to evolve as technology does, but with safety always as the top priority.

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