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ADA Accessibility Terms and Definitions

Published: 2013-06-05 - Updated: 2022-01-29
Author: Disabled World | Contact: Disabled World (
Peer-Reviewed Publication: N/A
Additional References: Glossary and Definitions Publications

Synopsis: Glossary of Americans with Disabilities Act (ADA) accessibility terms and guidelines. The terms accessible design, usable design, and universal design are all approaches to design that can result in products that are easier for everyone to use, including people with disabilities. Accessibility as a design concern has a long history, but public awareness about accessibility increased with the passage of legislation such as the Americans with Disabilities Act (ADA), which mandated that public facilities and services be fully accessible to people with disabilities.


Main Digest

Accessibility refers to the design of products, devices, services, vehicles, or environments so as to be usable by people with disabilities. Accessibility can be viewed as the "ability to access" and benefit from some system or entity. The concept focuses on enabling access for people with disabilities, or enabling access through the use of assistive technology; however, research and development in accessibility brings benefits to everyone.

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In this Glossary of ADA Terms listed below are common terms used in accessibility and their definitions relating to technology, disability and law.

Access Aisle

An accessible pedestrian space between elements, such as parking spaces, seating, and desks, that provides clearances appropriate for use of the elements.


Describes a site, building, facility, or portion thereof that complies with these guidelines.

Accessible Element

An element specified by these guidelines (for example, telephone, controls, and the like).

Accessible Route

A continuous unobstructed path connecting all accessible elements and spaces of a building or facility. Interior accessible routes may include corridors, floors, ramps, elevators, lifts, and clear floor space at fixtures. Exterior accessible routes may include parking access aisles, curb ramps, crosswalks at vehicular ways, walks, ramps, and lifts.

Accessible Space

Space that complies with these guidelines.


The ability of certain building spaces and elements, such as kitchen counters, sinks, and grab bars, to be added or altered so as to accommodate the needs of individuals with or without disabilities or to accommodate the needs of persons with different types or degrees of disability.


An expansion, extension, or increase in the gross floor area of a building or facility.

Administrative Authority

A governmental agency that adopts or enforces regulations and guidelines for the design, construction, or alteration of buildings and facilities.


An alteration is a change to a building or facility that affects or could affect the usability of the building or facility or part thereof. Alterations include, but are not limited to, remodeling, renovation, rehabilitation, reconstruction, historic restoration, resurfacing of circulation paths or vehicular ways, changes or rearrangement of the structural parts or elements, and changes or rearrangement in the plan configuration of walls and full-height partitions. Normal maintenance, re-roofing, painting or wallpapering, or changes to mechanical and electrical systems are not alterations unless they affect the usability of the building or facility.

Amusement Attraction

Any facility, or portion of a facility, located within an amusement park or theme park which provides amusement without the use of an amusement device. Examples include, but are not limited to, fun houses, barrels, and other attractions without seats.

Amusement Ride

A system that moves persons through a fixed course within a defined area for the purpose of amusement.

Amusement Ride Seat

A seat that is built-in or mechanically fastened to an amusement ride intended to be occupied by one or more passengers.

Area of Rescue Assistance

An area, which has direct access to an exit, where people who are unable to use stairs may remain temporarily in safety to await further instructions or assistance during emergency evacuation.

Area of Sport Activity

That portion of a room or space where the play or practice of a sport occurs.

Assembly Area

A room or space accommodating a group of individuals for recreational, educational, political, social, civic, or amusement purposes, or for the consumption of food and drink.

Automatic Door

A door equipped with a power-operated mechanism and controls that open and close the door automatically upon receipt of a momentary actuating signal. The switch that begins the automatic cycle may be a photoelectric device, floor mat, or manual switch (see power-assisted door).

Boarding Pier

A portion of a pier where a boat is temporarily secured for the purpose of embarking or disembarking.

Boat Launch Ramp

A sloped surface designed for launching and retrieving trailered boats and other water craft to and from a body of water.

Boat Slip

That portion of a pier, main pier, finger pier, or float where a boat is moored for the purpose of berthing, embarking, or disembarking.


Any structure used and intended for supporting or sheltering any use or occupancy.

Catch Pool

A pool or designated section of a pool used as a terminus for water slide flumes.

Circulation Path

An exterior or interior way of passage from one place to another for pedestrians, including, but not limited to, walks, hallways, courtyards, stairways, and stair landings.



Clear Floor Space

The minimum unobstructed floor or ground space required to accommodate a single, stationary wheelchair and occupant.

Closed Circuit Telephone

A telephone with dedicated line(s) such as a house phone, courtesy phone or phone that must be used to gain entrance to a facility.

Common Use

Refers to those interior and exterior rooms, spaces, or elements that are made available for the use of a restricted group of people (for example, occupants of a homeless shelter, the occupants of an office building, or the guests of such occupants).

Cross Slope

The slope that is perpendicular to the direction of travel (see running slope).

Curb Ramp

A short ramp cutting through a curb or built up to it.

Detectable Warning

A standardized surface feature built in or applied to walking surfaces or other elements to warn visually impaired people of hazards on a circulation path.

Dwelling Unit

A single unit which provides a kitchen or food preparation area, in addition to rooms and spaces for living, bathing, sleeping, and the like. Dwelling units include a single family home or a townhouse used as a transient group home; an apartment building used as a shelter; guest-rooms in a hotel that provide sleeping accommodations and food preparation areas; and other similar facilities used on a transient basis. For purposes of these guidelines, use of the term "Dwelling Unit" does not imply the unit is used as a residence.

Egress, Means of

A continuous and unobstructed way of exit travel from any point in a building or facility to a public way. A means of egress comprises vertical and horizontal travel and may include intervening room spaces, doorways, hallways, corridors, passageways, balconies, ramps, stairs, enclosures, lobbies, horizontal exits, courts and yards. An accessible means of egress is one that complies with these guidelines and does not include stairs, steps, or escalators. Areas of rescue assistance or evacuation elevators may be included as part of accessible means of egress.


An architectural or mechanical component of a building, facility, space, or site, e.g., telephone, curb ramp, door, drinking fountain, seating, or water closet.

Elevated Play Component

A play component that is approached above or below grade and that is part of a composite play structure consisting of two or more play components attached or functionally linked to create an integrated unit providing more than one play activity.


Any access point to a building or portion of a building or facility used for the purpose of entering. An entrance includes the approach walk, the vertical access leading to the entrance platform, the entrance platform itself, vestibules if provided, the entry door(s) or gate(s), and the hardware of the entry door(s) or gate(s).


All or any portion of buildings, structures, site improvements, complexes, equipment, roads, walks, passageways, parking lots, or other real or personal property located on a site.


A variable-sloped pedestrian walkway that links a fixed structure or land with a floating structure. Gangways which connect to vessels are not included.

Golf Car Passage

A continuous passage on which a motorized golf car can operate.

Ground Floor

Any occupiable floor less than one story above or below grade with direct access to grade. A building or facility always has at least one ground floor and may have more than one ground floor as where a split level entrance has been provided or where a building is built into a hillside.

Ground Level Play Component

A play component that is approached and exited at the ground level.

Mezzanine or Mezzanine Floor

That portion of a story which is an intermediate floor level placed within the story and having occupiable space above and below its floor.

Marked Crossing

A crosswalk or other identified path intended for pedestrian use in crossing a vehicular way.

Multifamily Dwelling

Any building containing more than two dwelling units.


A room or enclosed space designed for human occupancy in which individuals congregate for amusement, educational or similar purposes, or in which occupants are engaged at labor, and which is equipped with means of egress, light, and ventilation.

Operable Part

A part of a piece of equipment or appliance used to insert or withdraw objects, or to activate, deactivate, or adjust the equipment or appliance (for example, coin slot, pushbutton, handle).

Play Area

A portion of a site containing play components designed and constructed for children.

Play Component

An element intended to generate specific opportunities for play, socialization, or learning. Play components may be manufactured or natural, and may be stand alone or part of a composite play structure.

Power-assisted Door

A door used for human passage with a mechanism that helps to open the door, or relieves the opening resistance of a door, upon the activation of a switch or a continued force applied to the door itself.

Private Facility

A place of public accommodation or a commercial facility subject to title III of the ADA and 28 C.F.R. part 36 or a transportation facility subject to title III of the ADA and 49 C.F.R. 37.45.

Public Facility

A facility or portion of a facility constructed by, on behalf of, or for the use of a public entity subject to title II of the ADA and 28 C.F.R. part 35 or to title II of the ADA and 49 C.F.R. 37.41 or 37.43.

Public Use

Describes interior or exterior rooms or spaces that are made available to the general public. Public use may be provided at a building or facility that is privately or publicly owned.


A walking surface which has a running slope greater than 1:20.

Running Slope

The slope that is parallel to the direction of travel (see cross slope).

Service Entrance

An entrance intended primarily for delivery of goods or services.


Displayed verbal, symbolic, tactile, and pictorial information.


A parcel of land bounded by a property line or a designated portion of a public right-of-way.

Site Improvement

Landscaping, paving for pedestrian and vehicular ways, outdoor lighting, recreational facilities, and the like, added to a site.

Sleeping Accommodations

Rooms in which people sleep; for example, dormitory and hotel or motel guest rooms or suites.

Soft Contained Play Structure

A play structure made up of one or more components where the user enters a fully enclosed play environment that utilizes pliable materials (e.g., plastic, netting, fabric).


A definable area, e.g., room, toilet room, hall, assembly area, entrance, storage room, alcove, courtyard, or lobby.


That portion of a building included between the upper surface of a floor and upper surface of the floor or roof next above. If such portion of a building does not include occupiable space, it is not considered a story for purposes of these guidelines. There may be more than one floor level within a story as in the case of a mezzanine or mezzanines.

Structural Frame

The structural frame shall be considered to be the columns and the girders, beams, trusses and spandrels having direct connections to the columns and all other members which are essential to the stability of the building as a whole.

TDD (Telecommunication Devices for the Deaf)

See text telephone.

TTY (Tele-Typewriter)

See text telephone.


Describes an object that can be perceived using the sense of touch.

Technically Infeasible

See 4.1.6(1)(j) EXCEPTION.

Teeing Ground

In golf, the starting place for the hole to be played.

Text Telephone (TTY)

Machinery or equipment that employs interactive text based communications through the transmission of coded signals across the standard telephone network. Text telephones can include, for example, devices known as TDDs (telecommunication display devices or telecommunication devices for deaf persons) or computers with special modems. Text telephones are also called TTYs, an abbreviation for tele-typewriter.

Transfer Device

Equipment designed to facilitate the transfer of a person from a wheelchair or other mobility device to and from an amusement ride seat.

Transient Lodging

A building, facility, or portion thereof, excluding inpatient medical care facilities and residential facilities, that contains sleeping accommodations. Transient lodging may include, but is not limited to, resorts, group homes, hotels, motels, and dormitories.

Transition Plate

A sloping pedestrian walking surface located at the end(s) of a gangway.

Use Zone

The ground level area beneath and immediately adjacent to a play structure or equipment that is designated by ASTM F 1487 Standard Consumer Safety Performance Specification for Playground Equipment for Public Use for unrestricted circulation around the equipment and on whose surface it is predicted that a user would land when falling from or exiting the equipment.

Vehicular Way

A route intended for vehicular traffic, such as a street, driveway, or parking lot.


An exterior pathway with a prepared surface intended for pedestrian use, including general pedestrian areas such as plazas and courts.

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Cite This Page (APA): Disabled World. (2013, June 5). ADA Accessibility Terms and Definitions. Disabled World. Retrieved December 2, 2022 from

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