Thank you to MCity for providing a glossary that served as the basis for this page. This glossary is in no way complete or conclusive – a list of further resources, including a number of excellent glossaries and term lists, can be found at the bottom of this page.
Levels of Automation
Assisted driving features
- Level 0 – You’re driving.
- Level 1 – You’re driving, but you’re assisted with either steering or speed.
- Level 2 – You’re driving, but you’re assisted with both steering and speed.
Automated driving features
- Level 3 – You’re not driving, but you will need to drive if prompted in order to maintain safety.
- Level 4 – You’re not driving, but either:
- a) you will need to drive if prompted in order to reach your destination (in a vehicle you can drive); or
- b) you will not be able to reach every destination (in a vehicle you can’t drive).
- Level 5 – You’re not driving, and you can reach any destination.
5G (5th Generation)
Latest generation of cellular mobile communications that allows for have high data transmission speeds, reduced latency, energy savings, cost reductions, higher system capacities, and the capability for massive device connectivity.
The ability of any given individual to utilize a transportation system. Accessibility is primarily discussed in relation to people with disabilities and other mobility challenges.
Adaptive Cruise Control
Technology that allows a vehicle to automatically adjust its speed to maintain a safe distance between it and other vehicles.
Advanced Driver Assistance Systems (ADAS)
Safety features designed to avoid collisions and accidents by offering technologies that alert the driver to potential problems, or to avoid collisions by implementing safeguards and taking over control of the vehicle. These features can include automated lighting, adaptive cruise control, automated braking, GPS/ traffic warnings, alerts to drivers regarding other cars or dangers, lane keeping, or cameras/displays showing what is in a vehicle’s blind spots.
Parts or components installed in a vehicle after it has been purchased. These parts are usually not sourced from a vehicle’s original equipment manufacturer.
Automated Driving System (ADS)
The system used to automate a vehicle’s operation. This includes the sensors used to observe the world around the vehicle, the systems used to control the vehicle’s speed and direction, and the computer systems used for decision-making.
Automatic Emergency Braking (AEB)
System that allows a vehicle to slow or stop independently of human control when it senses a crash or collision is imminent. The capabilities and range of these systems can vary.
Computer Vision (Machine Vision)
Computer-based analysis of images via a camera or other sensor system. For example, an automated vehicle would use a computer vision system to analyze the input from its cameras to identify and differentiate road signs – i.e. tell a stop sign from a yield sign.
Connected Vehicle (CV)
A vehicle equipped with wireless communication systems that allows it to connect and communicate with other objects in its environment, like other vehicles or pieces of infrastructure.
Connected and Automated Vehicle (CAV)
A vehicle equipped with both CV and AV technologies. The term CAV is also frequently used as a catchall to refer to an array of automotive-based emerging transportation technologies.
Systems and practices used to protect digital systems and networks from unauthorized access, disruptions, and damage.
Dedicated Short Range Communication (DSRC)
A protocol for the transmission of information between multiple vehicles (V2V) and between vehicles and transportation infrastructure (V2I) using dedicated portions of the radio spectrum. The system does not require any communication infrastructure for vehicles to communicate, allowing it to function in remote or little-developed areas. The section of the radio spectrum originally dedicated to DSRC has been part of an ongoing debate and was partially reallocated by the FCC in 2020 for use by wifi devices.
Electric scooter – small electric-powered motorized scooters that have gained popularity as a form of micromobility. These vehicles are typically smaller than the gas-powered scooters popular around the globe.
Electric Vehicle (EV)
A vehicle (automobile, scooter, aircraft, etc.) powered by a rechargeable battery rather than an internal combustion engine or other power source.
Event Data Recorder (EDR)
Device that records information related to vehicle crashes or accidents.
First Mile/Last Mile
The portion of a trip between the end point of a form of transportation and an individual’s origin/destination. For example, the distance between a transit stop or open parking lot/space and an initial or final destination.
A digital barrier that fences off where a vehicle (like an automated vehicle, e-scooter, or drone) can operate.
Highly Automated Vehicles (HAV)
Vehicles equipped with automated driving systems that meet SAE Levels 3-5, meaning that the ADS can take full control of a vehicle, requiring no human input, for at least some portion of the driving process.
Human Machine Interface or Interaction (HMI)
The relationship between humans and a machine system. In vehicles this can include software applications that present information to an operator or user about the state of a digital system, and the controls designed to accept and implement an operator’s instructions.
Intelligent Transportation Systems (ITS)
The application of advanced information and communications technology to surface transportation in order to achieve enhanced safety and mobility while reducing the environmental impact of transportation.
Internet of Things (IoT)
The ever-growing network of digitally connected items. This can include vehicles, phones, household appliances, medical devices, etc. – anything intended to in some way connect to a wider computer network.
The ability of two or more systems or components to exchange information and use what has been exchanged.
In-Vehicle Infotainment or Infotainment System
The equipment and software installed in a vehicle to provide entertainment and information to drivers/passengers – i.e. the radio, navigation system, or in-vehicle Wi-Fi.
LiDAR (Light Detection and Ranging)
A remote sensing method used to examine the an environment via a pulsed laser to measure ranges. LiDAR can be used to create high-resolution maps and 3D images of a vehicle’s surrounding environment.
Artificial intelligence technology that allows computer systems to learn from input and alter their programming and behavior over time based on that input.
Catch-all term for small, lightweight vehicles that typically carry one person and travel at low speed. These include bicycles (including bike-sharing systems), e-bikes and e-scooters, among other options.
Mobility as a Service (MaaS)
An entity or company that integrates various forms of transportation services into a single on-demand platform. Uber and Lyft are two prominent examples of MaaS, as they provide not only automobile transport, but also micro-mobility access via their apps.
Operational Design Domain
The specific conditions and situations under which a system (such as an ADS or ADAS) is intended to operate. This domain can be limited by geography, vehicle speed, weather conditions, etc.
Original Equipment Manufacturer (OEM)
As used in the automotive industry, the company that originally manufactured the final complete vehicle (i.e. Ford, GM, Tesla, Honda, etc.).
Services that require approval from a user before they can be utilized. For example, a ride-sharing company may required users to share their location data before being able to summon a ride.
Over-the-Air (OTA) Update
Software or firmware updates to a device (or vehicle) that are transmitted wirelessly to a vehicle from the internet or a cloud service.
Grouping vehicles together to increase road capacity and efficiency by using automated and connected systems to enable vehicles to travel in tandem much more closely together than currently allowed by law (or would be safe while under human control).
An AV used to carry passengers for a fee.
Computing device located on the roadside that provides connectivity support to passing vehicles.
The integration of connected transportation technology into wider society and the larger emerging digital infrastructure such as the Internet of Things. The benefits of integrating these systems include more efficient traffic management, improved access to transit, and reduced emissions.
The use of wireless devices and “black box” technologies to transmit data in real time. Typically, it’s used in the context of automobiles, whereby installed or after-factory boxes collect and transmit data on vehicle use, maintenance requirements or automotive servicing.
Areas with limited transportation supply. These deficiencies can include poor road conditions, little to no access to transit, and the lack of sidewalks.
Transportation Network Company (TNC)
Business model that allows individuals to arrange a ride with a vehicle via an app or other technological solution. The vehicles can be operated by another human (as in the case of Uber or Lyft) or could be operated by the individual seeking a ride (as in the case of Zipccar).
An approach to design that is intended to accommodate users with a wide array of needs and abilities.
Unmanned Aerial Vehicle (UAV)
Aircraft without a human pilot. Commonly known as “drones,” these can operate autonomously or under remote control.
Urban Air Mobility (UAM)
Proposed ecosystem of UAVs and other aircraft using automation and communication technologies to coordinate their movements through urban areas at altitudes lower than traditional aircraft.
Set of commands or menus through which a user communicates with a program
Vehicle Miles or Kilometers Traveled (VMT or VKT)
Measure of the total number of miles/kilometers traveled by all of the vehicles in a given geographic area over a given period. This measurement is used in a number of ways in transportation planning, and is seen as a marker of transportation demand.
Vehicle to Infrastructure (V2I) Communication
Communication between a vehicle and pieces of infrastructure (stoplights, rail crossings, tolls, etc.).
Vehicle to Vehicle (V2V) Communication
Communication and information exchange between two or more vehicles.
Vehicle to X (V2X) Communication
Communication between vehicles and other connected digital equipment – including, but not limited to, infrastructure and other vehicles.
Vertical Takeoff and Landing (VTOL)
Aircraft capable of taking off and landing vertically, eliminating the need for a runway. Helicopters are the most wide-spread version of these aircraft in current use, though propeller or jet powered VTOL aircraft are in use by militaries. A number of urban air mobility proposals are built around automated (and often electric) VTOL aircraft for cargo and passenger use.
Vulnerable Road User (VRU)
Road users without the protection of an automobile, such as pedestrians and cyclists.
Nonprofit, nonpartisan association representing highway and transportation departments in the fifty states and all five transportation modes: air, highways, public transportation, rail, and water, with the goal of fostering the development, operation, and maintenance of an integrated national transportation system.
A Department of Defense (DoD) agency that supports the development of new technologies. One of their programs is the DARPA Grand Challenge prize competition for Autonomous Vehicles, in which university teams enter and work with automotive and tech companies.
Federal civil aviation agency that regulates aircraft safety, certifies pilots and airports, and monitors and manages air traffic. Part of the U.S. Department of Transportation.
Independent federal commission (lead by five commissioners) that regulates communication industries and technologies, including radio, television, and satellite communications. The FCC is responsible for regulating the use of radio spectrum, and allocates different ranges of spectrum for different uses.
Federal agency that coordinates highway programs, including operating programs that fund construction and maintenance. Part of the U.S. Department of Transportation.
Federal agency that regulates commercial motor-vehicles, including interstate buses and cargo trucking. Part of the U.S. Department of Transportation.
Federal agency responsible for regulating rail transportation safety and the railroad industry. Part of the U.S. Department of Transportation.
Federal agency that assists states and cities in developing and maintaining mass transit systems. Part of the U.S. Department of Transportation.
The nation’s largest organization dedicated to advancing the research, development and deployment of intelligent transportation systems to improve the nation’s surface transportation system.
Federal agency that sets and enforces motor vehicle safety standards, while also promoting traffic safety and other automobile-related issues. Part of the U.S. Department of Transportation.
Independent federal agency that investigates transportation accidents. The board does not have regulatory authority, but can make recommendations to other agencies based on their investigations. As an independent agency it is separate from the U.S. Department of Transportation or any other department or agency.
SAE International (SAE)
Formerly the Society of Automotive Engineers, SAE International is an organization of engineers from the automotive and aerospace industries. The organization sets engineering standards that are used globally.
Section of the National Academies of Sciences, Engineering, and Medicine focused on transportation. TRB facilitates the sharing of information on transportation practice and policy by researchers and practitioners.
Uniform Law Commission (ULC)
Organization that provides lawmakers with non-partisan model laws drafted and discussed by legal experts.
U.S. Department of Transportation (DOT or USDOT)
Federal department that manages the U.S.’s transportation infrastructure and industries via a number of administrations (some of which are noted above).
The following resources were extremely helpful in the creation of this list, and are excellent sources for more detailed descriptions of many of the above terms and concepts.
- Bryant Walker Smith – Automated Driving Definitions
- University of Virginia Center for Transportation Studies – Glossary of Connected and Automated Vehicle Terms
- Institute of Electrical and Electronics Engineers (IEEE) – Ethically Aligned Design First Edition Glossary
- Victoria Transport Policy Institute – TDM Encyclopedia and Glossary
- Transportation Research Board – Urban Public Transportation Glossary