California Code, Public Utilities Code - PUC § 460.3

(a) The commission shall prohibit any passenger stage corporation from charging any fare to, or imposing any other charge on, any physically disabled or handicapped passenger which is more than the fare or charge imposed on a passenger who is not physically disabled or handicapped for the same transportation or service, and shall approve no schedule of fares or charges which is discriminatory under this section.

(b) Any special provision made by a passenger stage corporation for assisting a physically disabled or handicapped person in using its transportation service is, for purposes of subdivision (a), a part of the same transportation or service offered to passengers who are not physically disabled or handicapped, and is not a separate service for which an additional charge may be made.  Nothing in this section, however, requires a passenger stage corporation to furnish any equipment or assistance for a physically disabled or handicapped person different from or in addition to that which may be required under any other law.