28 CFR Part 36 Nondiscrimination on the Basis of Disability by Public Accommodations and in Commercial Facilities (1991 ADA Title III Regulations)

(d) Check-out aisles. A store with check-out aisles shall ensure that an adequate number of accessible check-out aisles are kept open during store hours, or shall otherwise modify its policies and practices, in order to ensure that an equivalent level of convenient service is provided to individuals with disabilities as is provided to others. If only one check-out aisle is accessible, and it is generally used for express service, one way of providing equivalent service is to allow persons with mobility impairments to make all their purchases at that aisle.