Section 37.193 - Interim service requirements(a) Until 100 percent of the fleet of a large or small operator uses to provide fixed-route service is composed of accessible OTRBs, the operator shall meet the following interim service requirements:(1) Beginning one year from the date on which the requirements of this subpart begin to apply to the operator, it shall ensure that any individual with a disability that requests service in an accessible OTRB receives such service. (i) The operator may require up to 48 hours' advance notice to provide this service.(ii) If the individual with a disability does not provide the advance notice the operator requires, the operator shall nevertheless provide the service if it can do so by making a reasonable effort.(iii) If the trip on which the person with a disability wishes to travel is already provided by an accessible bus, the operator has met this requirement.(2) Interim service under this paragraph (a) is not required to be provided by a small operator who is providing equivalent service to its fixed-route service as provided in § 37.183(b)(2) .(b) Some small fixed-route operators may never have a fleet 100 percent of which consists of accessible buses (e.g., a small fixed-route operator who exclusively or primarily purchases or leases used buses). Such an operator must continue to comply with the requirements of this section with respect to any service that is not provided entirely with accessible buses.56 FR 45621, Sept. 6, 1991, as amended at 76 FR 57936 , Sept. 19, 2011