evidence: (19) Where provided, baggage check-in and retrieval systems shall be on an accessible route complying with 4.3, and shall have space immediately adjacent complying with 4.2. If unattended security barriers are provided, at least one gate shall comply with 4.13. Gates which must be pushed open by wheelchair or mobility aid users shall have a smooth continuous surface extending from 2 inches above the floor to 27 inches above the floor. [...] Section 36.211 Maintenance of Accessible Features Section 36.211 provides that a public accommodation shall maintain in operable working condition those features of facilities and equipment that are required to be readily accessible to and usable by persons with disabilities by the Act or this part. The Act requires that, to the maximum extent feasible, facilities must be accessible to, and usable by, individuals with disabilities. This section recognizes that it is not sufficient to provide features such as accessible routes, elevators, or ramps, if those features are not maintained in a manner that enables individuals with disabilities to use them. Inoperable elevators, locked accessible doors, or "accessible’’ routes that are obstructed by furniture, filing cabinets, or potted plants are neither "accessible to’’ nor "usable by’’ individuals with disabilities.