(a) When a public entity enters into a contractual or other arrangement (including, but not limited to, a grant, subgrant, or cooperative agreement) or relationship with a private entity to operate fixed route or demand responsive service, the public entity shall ensure that the private entity meets the requirements of this part that would apply to the public entity if the public entity itself provided the service.

(b) A private entity which purchases or leases new, used, or remanufactured vehicles, or remanufactures vehicles, for use, or in contemplation of use, in fixed route or demand responsive service under contract or other arrangement or relationship with a public entity, shall acquire accessible vehicles in all situations in which the public entity itself would be required to do so by this part.

(c) A public entity which enters into a contractual or other arrangement (including, but not limited to, a grant, subgrant, or cooperative agreement) or relationship with a private entity to provide fixed route service shall ensure that the percentage of accessible vehicles operated by the public entity in its overall fixed route or demand responsive fleet is not diminished as a result.

(d) A private entity that provides fixed route or demand responsive transportation service under contract or other arrangement (including, but not limited to, a grant, subgrant, or cooperative agreement) with another private entity shall be governed, for purposes of the transportation service involved, by the provisions of this part applicable to the other entity.