Schmeck,
As you know ADA only list broad classes of disabilities not the particular manifestation of the disability that may prevent equal accommodation.
Social impairment from Autism or other causes is covered under 1(i& ii) and 4(ii) when is it so severe are to limit life activities
Sec.36.301 Eligibility criteria.
(a) General. A public accommodation shall not impose or apply eligibility criteria that screen out or tend to screen out an individual with a disability or any class of individuals with disabilities from fully and equally enjoying any goods, services, facilities, privileges, advantages, or accommodations, unless such criteria can be shown to be necessary for the provision of the goods, services, facilities, privileges, advantages, or accommodations being offered.
(b) Safety. A public accommodation may impose legitimate safety requirements that are necessary for safe operation. Safety requirements must be based on actual risks and not on mere speculation, stereotypes, or generalizations about individuals with disabilities.
(c) Charges. A public accommodation may not impose a surcharge on a particular individual with a disability or any group of individuals with disabilities to cover the costs of measures, such as the provision of auxiliary aids, barrier removal, alternatives to barrier removal, and reasonable modifications in policies, practices, or procedures, that are required to provide that individual or group with the nondiscriminatory treatment required by the Act or this part.
Disability means, with respect to an individual, a physical or mental impairment that substantially limits one or more of the major life activities of such individual; a record of such an impairment; or being regarded as having such an impairment.
Who Is eligible:
(1) The phrase physical or mental impairment means --
(i) Any physiological disorder or condition, cosmetic disfigurement, or anatomical loss affecting one or more of the following body systems: neurological; musculoskeletal; special sense organs; respiratory, including speech organs; cardiovascular; reproductive; digestive; genitourinary; hemic and lymphatic; skin; and endocrine;
(ii) Any mental or psychological disorder such as mental retardation, organic brain syndrome, emotional or mental illness, and specific learning disabilities;
(iii) The phrase physical or mental impairment includes, but is not limited to, such contagious and noncontagious diseases and conditions as orthopedic, visual, speech, and hearing impairments, cerebral palsy, epilepsy, muscular dystrophy, multiple sclerosis, cancer, heart disease, diabetes, mental retardation, emotional illness, specific learning disabilities, HIV disease (whether symptomatic or asymptomatic), tuberculosis, drug addiction, and alcoholism;
(iv) The phrase physical or mental impairment does not include homosexuality or bisexuality.
(2) The phrase major life activities means functions such as caring for one's self, performing manual tasks, walking, seeing, hearing, speaking, breathing, learning, and working.
(3) The phrase has a record of such an impairment means has a history of, or has been misclassified as having, a mental or physical impairment that substantially limits one or more major life activities.
(4) The phrase is regarded as having an impairment means --
(i) Has a physical or mental impairment that does not substantially limit major life activities but that is treated by a private entity as constituting such a limitation;
(ii) Has a physical or mental impairment that substantially limits major life activities only as a result of the attitudes of others toward such impairment; or
(iii) Has none of the impairments defined in paragraph (1) of this definition but is treated by a private entity as having such an impairment.