Self-driving car

A self-driving car, also known as an autonomous car, driverless car, robotic car, or robo-car, is a car that is capable of operating with reduced or no human input. They are sometimes called robotaxis, though this term refers specifically to self-driving cars operated for a ridesharing company. As of 2026, the term "self-driving" lacks an agreed standard definition and is also subject to commercial advertising and branding considerations.

In 2020, Waymo was the first to offer rides in driverless taxis in the operational design domain (ODD) of limited geographic areas, but as of late 2025, no system has achieved full autonomy in all domains - sometimes referred to as "Level 5" on a scale of 0 to 5 levels of automation defined by the global standards organization SAE International, or simply "no driver" as given by the classification system proposed by Mobileye in the US.

Following a history of experimentation and development of advanced driver assistance systems (ADAS) after World War II, two main technologies are now primarily used: LiDAR (Light Detection and Ranging), and visual sensors (cameras) which capture images and video like human eyes. These are combined with systems such as Global Positioning System (GPS), neural networks, artificial intelligence, and established ADAS engineering to deliver levels of driving autonomy.

The primary obstacle to self-driving is the advanced software and mapping required to make them work safely across the wide variety of conditions that drivers experience. However, the software is not yet advanced enough to handle all circumstances and has caused accidents and deaths. Other issues include security of over-the-air updates, legal and regulatory issues, ethics, and consumer confidence. Methods of testing and monitoring the reliability of cars have evolved in parallel with deployment, with various standards being proposed. Implications for urban infrastructure and the economy have also been discussed.

Public perception and acceptance of autonomous cars has been mixed. A survey in 2022 found only 27% of the world's population would feel safe in one. Public acceptance is also influenced by "self-AV bias", where drivers judge identical autonomous vehicle driving much more harshly than human.

History

Definitions

Organizations such as the global standards body SAE International (SAE) have proposed terminology to describe technical capabilities. However, most terms have no standard definition and are employed variously by vendors and others. Proposals to adopt aviation automation terminology for cars has also not prevailed.

The first consideration is the operational design domain (ODD). The concept presumes that automated systems have limitations. Relating system function to the ODD it supports is important for developers and regulators to establish and communicate safe operating conditions. Systems should operate within those limitations. Some systems recognize the ODD and modify their behavior accordingly. For example, an autonomous car might recognize that traffic is heavy and disable its automated lane change feature.

Vendors have taken a variety of approaches to the self-driving problem. Tesla's approach is to allow their "full self-driving" (FSD) system to be used in all ODDs as a Level 2 (hands/on, eyes/on) ADAS. Waymo picked specific ODDs (city streets in Phoenix and San Francisco) for their Level 5 robotaxi service. Mercedes Benz offers Level 3 service in Las Vegas in highway traffic jams at speeds up to 40 miles per hour (64 km/h). Mobileye's SuperVision system offers hands-off/eyes-on driving on all road types at speeds up to 130 km/h (81 mph). GM's hands-free Super Cruise operates on specific roads in specific conditions, stopping or returning control to the driver when ODD changes. In 2024 the company announced plans to expand road coverage from 400,000 miles to 750,000 miles (1,210,000 km). Ford's BlueCruise hands-off system operates on 130,000 miles (210,000 km) of US divided highways.

Names such as AutonoDrive, PilotAssist, "Full-Self Driving" or DrivePilot are used even though the products offer an assortment of features that may not match the names. Despite offering a system dubbed Full Self-Driving, Tesla stated that its system did not autonomously handle all driving tasks. In the United Kingdom, a fully self-driving car is defined as a car so registered, rather than one that supports a specific feature set. The Association of British Insurers claimed that the usage of the word autonomous in marketing was dangerous because car ads make motorists think "autonomous" and "autopilot" imply that the driver can rely on the car to control itself, even though they do not.

Concepts

The following are useful in understanding the various definitions and criteria in use for self-driving cars.

Driving systems

Advanced driver-assistance systems (ADAS) automate specific driving features such as Forward Collision Warning (FCW), Automatic Emergency Braking (AEB), Lane Departure Warning (LDW), Lane Keeping Assistance (LKA) or Blind Spot Warning (BSW). An ADAS requires a human driver to handle tasks that the ADAS does not support.

ADAS contrasts to an automated driving system (ADS), which would be classified by SAE J3016 as Level 3 or higher.

Autonomy versus automation

Autonomy implies that an automation system is under the control of the vehicle rather than a driver. Automation is function-specific, handling issues such as speed control, but leaves broader decision-making to the driver.

The European car safety performance assessment programme Euro NCAP defines "autonomous" as "the system acts independently of the driver to avoid or mitigate the accident".

In Europe, the words automated and autonomous can be used together. For instance, under Regulation (EU) 2019/2144:

"automated vehicle" means a vehicle that can move without continuous driver supervision, but that driver intervention is still expected or required in the operational design domains (ODD);

"fully automated vehicle" means a vehicle that can move entirely without driver supervision;

Cooperative system

A remote driver is a driver that operates a vehicle at a distance, using a video and data connection.

According to SAE J3016,Some driving automation systems may indeed be autonomous if they perform all of their functions independently and self-sufficiently, but if they depend on communication and/or cooperation with outside entities, they should be considered cooperative rather than autonomous.

Self-driving…