What do we mean by ensuring access for people with disabilities? Why ensure access for people with disabilities? When should you ensure access for people with disabilities? Who should ensure access for people with disabilities? How do you ensure access for people with disabilities? How do you engage in disability advocacy? Many features of everyday environments are easy to overlook when they work for us. Curbs, stairs, narrow doorways, signs, websites, public announcements, forms, transportation systems, and workplace procedures can all make it easier or harder for people to participate in community life. For a wheelchair user, a building without an accessible entrance may prevent access entirely. A person who is Deaf or hard of hearing may miss information provided only through a loudspeaker. A person who is blind or has low vision may encounter barriers when information is available only visually. Someone with a cognitive, learning, communication, neurological, or mental health disability may encounter other barriers when information, services, or environments are not designed with a range of needs in mind. These barriers are not inevitable. Accessibility can often be built into environments, programs, communication, technology, employment, education, transportation, and public participation from the beginning. This section discusses ways communities can identify and remove barriers so that people with disabilities can participate fully in employment, education, services, public spaces, government, recreation, and community life. What do we mean by ensuring access for people with disabilities? Disability includes a wide range of physical, sensory, intellectual, developmental, cognitive, neurological, learning, communication, mental health, and other conditions. Disabilities may be apparent or non-apparent, lifelong or acquired later in life, and may affect people differently in different environments. Under the Americans with Disabilities Act (ADA), disability is defined broadly in relation to a physical or mental impairment that substantially limits one or more major life activities, a record of such an impairment, or being regarded as having such an impairment. Accessibility means creating environments, systems, information, services, and opportunities that people with disabilities can use and participate in on an equitable basis. Disability is shaped not only by a person's condition, but also by the barriers or supports in the surrounding environment. A wheelchair user may participate fully in a workplace when entrances, workspaces, restrooms, transportation, and emergency procedures are accessible. A Deaf employee may participate fully when effective communication is available. A person with a cognitive or learning disability may benefit from information presented in clear and accessible formats. Removing barriers does not mean that a person's disability disappears. It means that the environment no longer unnecessarily restricts that person's participation. Language related to disability continues to evolve, and individual preferences differ. People with disabilities is widely used as person-first language. Some people and disability communities prefer identity-first language such as disabled people, Autistic people, or Deaf people. When possible, respect the language people use for themselves. Avoid euphemisms such as "differently abled" and outdated terms such as "the handicapped." Terms such as "special needs" may also be less specific than simply describing a person's disability, access needs, or support needs. Types of disabilities Disability experiences vary widely, and the categories below are not exhaustive. A person may also experience more than one type of disability. Mobility and physical disabilities Mobility and physical disabilities may affect walking, standing, balance, movement, dexterity, strength, stamina, or use of the hands and arms. People may use wheelchairs, walkers, canes, prostheses, braces, other mobility devices, or no mobility device at all. Environmental features such as stairs, narrow passages, heavy doors, inaccessible restrooms, high counters, or poorly maintained sidewalks may create barriers. Sensory disabilities Deafness and hearing loss. People may communicate through spoken language, American Sign Language or another sign language, captioning, assistive listening technology, text, or a combination of approaches. Blindness and low vision. People may use screen readers, magnification, Braille, tactile information, white canes, service animals, audio information, or other tools and techniques. Communication disabilities Some disabilities affect speech, language, or other forms of communication. People may use speech-generating devices, text, communication boards, interpreters, assistants, or other forms of augmentative and alternative communication. Difficulty speaking does not indicate a person's intelligence or ability to understand information. Neurological and chronic health disabilities Conditions such as epilepsy, migraine, cerebral palsy, traumatic brain injury, chronic pain, and other neurological or chronic health conditions may affect mobility, concentration, communication, energy, sensory processing, or other activities. Some disabilities are episodic. A person's support or access needs may therefore change over time. Intellectual and developmental disabilities Intellectual and developmental disabilities include a broad range of conditions that may affect learning, communication, decision-making, daily activities, sensory processing, or other areas. People have different strengths, goals, and support needs. Some live and work independently, while others use varying levels of support. Avoid making assumptions about a person's abilities based on a diagnosis. Autism is a developmental disability that can affect communication, sensory processing, routines, social interaction, and other aspects of daily life in different ways. Autistic people vary greatly in their strengths, communication styles, support needs, and preferences. Learning and cognitive disabilities Learning disabilities can affect reading, writing, mathematics, memory, processing, organization, or other areas of learning. Dyslexia is one example. Learning disabilities are not a measure of overall intelligence. Some people also experience cognitive disabilities related to brain injury, neurological conditions, intellectual disabilities, or other causes. Mental health and psychiatric disabilities Mental health conditions may qualify as disabilities when they substantially limit major life activities. Conditions may include major depressive disorder, bipolar disorder, schizophrenia, post-traumatic stress disorder, anxiety disorders, and others. People's experiences and treatment preferences vary. Access may involve flexible schedules, changes in the environment, communication supports, leave, remote participation where appropriate, or other individualized accommodations. Environmental sensitivities and other non-apparent conditions Some people experience significant symptoms related to fragrances, chemicals, lighting, noise, temperature, or other environmental conditions. Depending on the person's functional limitations and the setting, reducing exposure or making other changes may improve access. Non-apparent disabilities may also include chronic illnesses, epilepsy, diabetes, autoimmune conditions, chronic pain, mental health disabilities, and many other conditions. Do not assume that a person does not have a disability because it is not immediately visible. Service animals Some people with disabilities use trained service animals to assist with disability-related tasks. Examples include guiding a person who is blind, alerting a Deaf person to sounds, retrieving objects, assisting during a seizure, or performing disability-related tasks for a person with a psychiatric disability. Rules concerning service animals differ according to the law and setting. In the United States, organizations should use current ADA guidance rather than relying on assumptions about an animal or a person's disability. Access for people with disabilities Accessibility includes several interconnected areas. Physical access Physical accessibility includes the ability to enter, move through, and use buildings and outdoor spaces. Depending on the setting, this may involve accessible routes, entrances, parking, passenger-loading areas, ramps, elevators, restrooms, counters, seating, signs, recreational facilities, and other features. Accessibility is strongest when it is incorporated into the original design rather than added later as a separate feature. Access to communication and information Information should be available in forms that people with different communication, sensory, cognitive, and learning needs can use. Depending on the situation, this may include: Captions and transcripts Sign language interpretation Assistive listening systems Braille, tactile, large-print, or audio information Plain-language information Accessible electronic documents Websites and mobile applications that work with assistive technology Communication devices or alternative forms of communication Visual as well as audible emergency and public announcements Program and service accessibility Accessibility also means that people with disabilities can participate in programs and obtain services without unnecessary barriers. This may require changes in policies, procedures, communication, scheduling, location, equipment, or the way a service is delivered. Employment Employment access includes nondiscriminatory recruitment, applications, interviews, hiring, training, advancement, workplace participation, and other terms and conditions of employment. Qualified applicants and employees with disabilities may need reasonable accommodations that allow them to participate in the application process, perform the essential functions of a position, or access the benefits and privileges of employment. Education Students with disabilities should have equitable access to education, instructional materials, school facilities, technology, extracurricular activities, communication, and other parts of the educational experience. Appropriate supports vary according to the student, educational setting, and applicable law. Community and civic access Accessibility includes opportunities to participate in recreation, cultural activities, religious life, community organizations, public meetings, government services, transportation, and civic life. It also includes accessible voting, public information, meetings, and other opportunities to participate in community decision-making. Why ensure access for people with disabilities? Accessibility is a civil rights issue. People with disabilities have the right to participate in community life without discrimination. Laws in the United States and many other countries establish accessibility and nondiscrimination requirements. Accessibility supports autonomy and participation. Removing unnecessary barriers gives people greater ability to make their own choices about employment, education, services, recreation, relationships, and civic life. Communities benefit from the participation of people with disabilities. People with disabilities are workers, students, business owners, leaders, caregivers, artists, volunteers, customers, residents, and participants in every part of community life. Accessible design often benefits many people. Ramps, curb cuts, captions, clear signs, automatic doors, plain-language information, flexible communication, and other accessibility features can also benefit older adults, parents with strollers, people recovering from injuries, travelers carrying luggage, and many others. Accessibility can improve organizations and services. Designing for a wider range of users can improve communication, customer service, safety, usability, and organizational responsiveness. Accessibility helps build more inclusive communities. People should not have to overcome avoidable barriers in order to participate alongside their neighbors, coworkers, classmates, friends, and families. When should you ensure access for people with disabilities? Accessibility should be considered from the beginning rather than only after someone encounters a barrier. When new buildings, facilities, or public spaces are being designed. Accessibility can usually be integrated more effectively when it is part of the original design. When buildings or facilities are being renovated or altered. Review current accessibility standards and determine which requirements apply to the particular project rather than relying on a simple percentage rule. When historic buildings are being adapted for public use. Historic preservation and accessibility should be considered together using the requirements and alternatives applicable to the particular property. When parks, trails, recreation facilities, streets, and other public spaces are being improved. Include people with disabilities in planning routes, entrances, seating, recreation features, signs, transportation connections, restrooms, and other elements. When an organization moves or changes the way it provides services. A new facility, program, technology platform, application system, or service-delivery model provides an opportunity to address accessibility from the beginning. When websites, mobile applications, documents, or other digital systems are developed or updated. Digital accessibility should be part of design, procurement, development, testing, and maintenance. When emergency plans are developed or reviewed. Emergency communication, evacuation, sheltering, transportation, and continuity plans should account for people with a range of disabilities. When people report barriers. Complaints and requests for accommodations provide important information, but organizations should not wait for a complaint before examining accessibility. As part of ongoing evaluation. Technology, standards, programs, buildings, and community needs change. Accessibility should be reviewed periodically. Who should ensure access for people with disabilities? Accessibility is a shared responsibility, but people with disabilities should have meaningful roles in identifying barriers, setting priorities, developing solutions, and evaluating results. People with disabilities. People who experience barriers directly bring knowledge that may not be visible to designers, administrators, employers, or service providers. Participation should begin early enough to influence decisions rather than being added after plans are nearly complete. Disability-led and disability rights organizations. These organizations may provide expertise on accessibility, independent living, rights, policy, accommodations, and community participation. Centers for Independent Living and other community organizations. These organizations may provide training, peer support, accessibility knowledge, and connections with people who have a range of lived experiences. Public officials and public agencies. Governments may establish, implement, fund, or enforce accessibility requirements and should ensure that people with disabilities can participate in public programs and decision-making. Enforcement and civil rights agencies. Appropriate government agencies investigate complaints, provide guidance, and enforce applicable disability-rights laws. Employers. Employers can make recruitment, hiring, workplaces, communication, technology, training, advancement, and workplace benefits accessible. Educators and educational institutions. Schools and colleges can address physical, instructional, technological, communication, and program accessibility. Organizations that provide public or community services. Accessibility should be considered in facilities, programs, eligibility practices, communication, technology, and service delivery. Architects, planners, engineers, designers, and building professionals. Accessibility can be incorporated into buildings, transportation, public spaces, housing, digital systems, and other environments from the beginning. Developers and property owners. Designing for accessibility from the beginning can reduce the need for later retrofits and expand who can use a property. Technology designers, developers, vendors, and content creators. Digital accessibility depends on decisions made throughout design, procurement, development, testing, and content creation. How do you ensure access for people with disabilities? Accessibility is most effective when it is built into ordinary planning and decision-making rather than treated as a separate project or an exception for a small group of people. Begin with people with disabilities Include people with disabilities in accessibility assessment, planning, design, implementation, testing, and evaluation. Ask people what barriers they experience rather than assuming what they need. Different people with the same disability may use different strategies, technologies, communication methods, or accommodations. When someone requests an accommodation, focus on what would provide effective access rather than on whether the request matches what has been provided to someone else. Use accessible and universal design Universal design seeks to make environments, products, technology, and information usable by as many people as possible from the beginning. Universal design does not eliminate every need for individualized accommodations, but it can reduce the number of unnecessary barriers people encounter. Physical access Buildings and outdoor spaces should be evaluated using the accessibility standards that apply to the particular facility and jurisdiction. Features to consider may include: Accessible routes from sidewalks, transportation, parking, and passenger drop-off areas Accessible entrances and doors Ramps, elevators, lifts, and appropriate changes in level Accessible restrooms Accessible counters, service areas, seating, and workspaces Accessible parking and passenger-loading areas Clear floor and maneuvering space Accessible signs and wayfinding Accessible recreation facilities and outdoor routes Emergency evacuation and refuge planning Accessibility standards contain specific technical requirements, so designers and organizations should use current official standards rather than relying on generalized measurements or older guidance. Accessibility does not need to separate people with disabilities from everyone else. A park trail, entrance, recreation area, seating section, or public space can be designed so that people with and without disabilities use the same environment together whenever feasible. Businesses may also be eligible for federal tax incentives related to qualified accessibility improvements. Because eligibility and tax rules can change, organizations should use current IRS guidance when planning or claiming these benefits. Emergency access and planning Accessibility planning should include emergencies rather than assuming that ordinary accessibility features will always remain available. Consider: Accessible emergency exits and evacuation routes Procedures for people who cannot use stairs Visual, audible, and accessible digital alerts Emergency transportation Accessible shelters and temporary facilities Backup communication when power or technology fails Individualized planning when appropriate People with disabilities should be included in emergency planning and exercises. Access to communication and information Effective communication means that people with communication disabilities can receive information from and communicate with an organization as effectively as others. Appropriate approaches depend on the person, the setting, and the nature and complexity of the communication. Examples may include: Sign language interpreters Real-time captioning Captions on videos Assistive listening systems Large-print, Braille, tactile, or audio materials Screen-reader-compatible electronic materials Plain-language or easy-to-understand information Speech-to-text or text-to-speech technology Augmentative and alternative communication Visual and audible public announcements Do not assume one method works for everyone. For important or complex communication, ask the person which methods are effective for them and follow the requirements that apply to the organization. Digital accessibility Websites, mobile applications, online forms, documents, videos, learning platforms, kiosks, and other digital tools are increasingly important parts of community access. Digital accessibility may include: Keyboard navigation Compatibility with screen readers and other assistive technologies Text alternatives for meaningful images Captions and transcripts for multimedia Sufficient contrast and readable text Clear headings and navigation Accessible forms and error messages Accessible electronic documents Federal agencies are subject to Section 508 requirements for covered information and communication technology. Other entities may have accessibility responsibilities under the ADA, Section 504, state or local law, funding agreements, or other requirements. State and local governments should also consult current Title II requirements for web content and mobile applications. Access to services and programs Services must be non-discriminatory, and covered organizations may need to make reasonable modifications to policies, practices, or procedures so that people with disabilities can participate. Examples may include: Moving an activity to an accessible space Modifying a check-in or application procedure Providing an alternative communication method Adjusting a policy when necessary for disability access Providing services in another accessible manner when required and appropriate Allowing service animals as required by applicable law Accessibility should not mean providing an unnecessarily separate or lower-quality service. The goal is equitable participation and access. Accessibility also includes organizational culture. Staff should communicate respectfully, avoid assumptions about people's abilities, understand relevant accessibility procedures, and know how to respond when someone requests an accommodation or identifies a barrier. Service animals Organizations should train staff on current service-animal requirements. Under the ADA rules that apply to state and local government services and public accommodations, a service animal is generally a dog individually trained to perform work or tasks directly related to a person's disability. The ADA also contains separate provisions concerning individually trained miniature horses. Staff should not assume that a person's disability must be visible in order for a service animal to be legitimate. Different rules may apply in housing, air travel, employment, and under state or local law, so organizations should consult the requirements that apply to the particular setting. Employment Employment decisions should focus on whether an applicant or employee is qualified to perform the essential functions of a position, with or without reasonable accommodation. Reasonable accommodations may include: Adjusting equipment or workspaces Modifying schedules Providing accessible technology Providing interpreters or readers Changing how information is provided Job restructuring where appropriate Remote work where it is an effective and reasonable accommodation Other individualized changes that allow a qualified employee to perform essential job functions or receive equal employment benefits Employers generally may ask applicants whether they can perform the essential functions of a job, with or without reasonable accommodation, but disability-related questions and medical examinations are subject to specific rules during the hiring process. Safety standards should be connected to actual job requirements and individualized evidence rather than assumptions or stereotypes about disability. Employees with disabilities remain responsible for meeting legitimate performance and conduct expectations, with reasonable accommodations considered where required. Education In the United States, the Individuals with Disabilities Education Act (IDEA) establishes rights related to special education and related services for eligible children with disabilities. IDEA Part B generally applies to children ages 3 through 21, subject to specific state-law exceptions. Eligible students receive a free appropriate public education through an Individualized Education Program (IEP) developed through an individualized planning process that includes parents or caregivers and, when appropriate, the student. IDEA also requires that students with disabilities be educated with students without disabilities to the maximum extent appropriate. Removal from the regular educational environment should occur only when education there cannot be achieved satisfactorily with appropriate supplementary aids and services. Educational access can include: Accessible classrooms and facilities Accessible instructional materials and technology Communication access Assistive technology Appropriate academic and behavioral supports Accessible extracurricular programs and school activities Individualized accommodations and services where required Institutions of higher education also have disability nondiscrimination and accessibility obligations under applicable federal and state laws. The specific requirements differ from the K–12 special education system, so students and institutions should use current guidance applicable to higher education. Civic access People with disabilities should be able to participate in government services, public meetings, community planning, and elections on an equitable basis. Civic accessibility may involve: Accessible meeting locations Accessible public notices and documents Sign language interpretation or captioning where needed Accessible websites and online participation Accessible polling places and voting systems Reasonable modifications that allow participation How do you engage in disability advocacy? Disability advocacy includes self-advocacy, community organizing, education, accessibility planning, participation in public processes, enforcement of existing rights, and efforts to improve policies or practices that create barriers. People with disabilities and disability-led organizations should have central roles in determining priorities and strategies. Identify the barrier and the desired change Begin by clearly identifying what is preventing access. Is the problem: A physical barrier? Inaccessible communication? An inaccessible website or technology? A policy or procedure? Discriminatory treatment? A lack of appropriate accommodation? Inconsistent implementation of an existing accessibility policy? Defining the barrier clearly can help identify who has responsibility and which solutions are possible. Start with communication when appropriate Sometimes an organization may not realize that a barrier exists. Bringing the issue to the attention of the appropriate staff member, accessibility coordinator, administrator, employer, property manager, or other responsible person may lead to a solution. Explain the barrier, the effect it has on access, and what change would provide meaningful access. Keep records of important communications when the issue may require formal follow-up. Use established complaint and enforcement processes when needed When informal problem-solving does not resolve an accessibility or discrimination concern, administrative complaints, internal grievance procedures, disability-rights agencies, mediation, legal assistance, or court processes may be available. The appropriate process depends on the type of organization, law involved, location, and nature of the issue. Because filing requirements and deadlines can vary, use current official information or qualified legal assistance for a specific complaint. Work with disability-led organizations and other knowledgeable partners Centers for Independent Living, disability-rights organizations, Protection and Advocacy systems, legal organizations, accessibility professionals, and community groups may provide information, training, technical assistance, peer support, or legal guidance. Collaboration can also help identify whether a barrier experienced by one person reflects a broader accessibility problem. Participate in public policy and planning processes When an accessibility issue involves government policy, building standards, transportation, public services, or other public decisions, people with disabilities and community organizations can participate through established civic processes. These may include public meetings, advisory groups, hearings, public-comment opportunities, accessibility committees, planning processes, and communication with the public agencies responsible for the issue. Provide accurate information about the barrier, the people affected, applicable accessibility requirements, possible solutions, costs, and implementation considerations. Advisory groups and planning bodies should include people with a range of disabilities and access experiences. One person should not be expected to represent every disability or every member of the disability community. Work with designers, developers, inspectors, technology professionals, and service providers Collaboration early in a project can prevent barriers before they are built into a facility, program, or technology. Accessibility professionals and people with disabilities can help organizations understand how technical standards translate into actual use. Whenever possible, test buildings, public spaces, websites, applications, documents, and services with people who use different mobility devices, communication methods, and assistive technologies. Use public communication responsibly Media and community communication can help explain accessibility barriers, disability rights, community experiences, and possible solutions. Coverage should avoid portraying people with disabilities primarily as inspirational, tragic, dependent, or exceptional because of their disability. When people share personal experiences, they should have meaningful control over how their stories, disability, photographs, and identifying information are presented. Disability should not need to be made emotionally compelling before an accessibility concern is taken seriously. Continue evaluating accessibility Accessibility is an ongoing process. Buildings age, technology changes, programs evolve, staff change, and new barriers may emerge. Continue asking: Can people with different disabilities enter and use the space? Can people obtain information in forms they can use? Are websites, applications, and documents accessible? Are accommodation and modification requests handled effectively? Do staff understand accessibility procedures? Are emergency procedures inclusive? Are people with disabilities involved in evaluating the organization's accessibility? Are some people experiencing barriers that others are not? Have applicable standards, technologies, or legal requirements changed? Accessibility should not be measured only by whether an organization has received complaints. People may stop using an inaccessible service without ever filing one. Proactive assessment and direct participation from people with disabilities can identify barriers earlier. In Summary Accessibility means more than ramps, elevators, and accessible restrooms. It includes physical environments, communication, information, technology, employment, education, services, transportation, emergency planning, and civic participation. Disability is part of human diversity. People with disabilities have different strengths, preferences, identities, goals, and access needs, and no single solution will work for everyone. Strong accessibility efforts: Include people with disabilities in decisions that affect them Build accessibility into planning and design from the beginning Remove physical, communication, digital, programmatic, and social barriers Provide individualized accommodations or modifications where needed Use current accessibility standards and legal guidance Train staff and people responsible for implementation Create effective ways to identify and resolve accessibility concerns Evaluate accessibility over time The goal is not to make disability less visible or to expect people with disabilities to adapt to environments that were not designed with them in mind. The goal is to create communities in which people with disabilities can make choices, participate, contribute, and live their lives without unnecessary or discriminatory barriers. Contributor Phil Rabinowitz Resources Online Resources The ADA website has a huge amount of information, including the ADA Standards for Accessible Design. Access Unlimited provides helpful information on how a low-tech tool can be used by almost anyone to determine if building features such as toilets, door widths, and ramp slopes are in compliance with the Americans With Disabilities Accessibility Guidelines (ADAAG). The DOJ provides information on Accessibility of State and Local Government websites to people with disabilities, with tips for developers and links to a number of sites with more information. Anniversary of Americans with Disability Act: July 26 provides facts on disabilities in the U.S. population from the U.S. Census Bureau. Canadian Charter of Rights and Freedoms (part of Canadian Constitution) provides information on the rights that all people are guaranteed, including for those with disabilities. Canadian Human Rights Act states that all individuals should have an opportunity equal with other individuals to make for themselves the lives that they are able and wish to have and to have their needs accommodated, consistent with their duties and obligations as members of society, without being hindered in or prevented from doing so by discriminatory practices based on race, national or ethnic origin, colour, religion, age, sex, sexual orientation, marital status, family status, disability or conviction for an offence for which a pardon has been granted or in respect of which a record suspension has been ordered. Convention on the Rights of Persons with Disabilities was established to promote, protect and ensure the full and equal enjoyment of all human rights and fundamental freedoms by all persons with disabilities, and to promote respect for their inherent dignity. The Curb-Cut Effect by Angela Glover Blackwell. Laws and programs designed to benefit vulnerable groups, such as the disabled or people of color, often end up benefiting all of society. The Disability Resource Network of British Columbia offers descriptions and explanations of various kinds of disabilities and conditions, among other resources. Frequently Asked Questions about ADA. The Home Usability Network from the University of Montana's Research and Training Center on Disability in Rural Communities (RTC: Rural) is a group of individuals and organizations that bring together their knowledge, resources, and creativity to develop customized solutions to individual usability problems. Job Accommodations Network offers helpful tips to people with disabilities about the accommodations that they might take advantage of as an employee. List of various ADA publications detailing regulations and technical assistance. Making Homes Visitable details how to make homes visitable for those with mobility limitations and why it is important to do so. Project Civic Access details settlements with various municipal and state governments concerning accessibility. SF's New Ballpark: Beautiful Access discusses a recently built ballpark that was created to be accessible for all. Standards for Website Accessibility is from Section 508 of the Rehabilitation Act, and sets out regulations for Internet Accessibility for government agencies, with links for each regulation to explanations and suggestions for web developers. United Nations Standard Rules on Equalization of Opportunity for Persons with Disabilities (1993) is an international document intended to focus worldwide attention on the need for equal rights and opportunities for persons with disabilities. United States Access Board lists the Uniform Federal Accessibility Standards (alternative to ADA Standards for state and local government entities). The U.S. Equal Employment Opportunities Commission provides information about federal laws that make it illegal to discriminate against a job applicant or an employee because of the person's race, color, religion, sex (including pregnancy), national origin, age (40 or older), disability or genetic information. It also provides information for employers on Prohibited Practices. Web Accessibility Initiative of the World Wide Web Consortium, with detailed information about accessibility for web developers.