38 C.F.R. § 70.73
(b) Travel without a reservation. Eligible persons who have provided the facility director or designee with the information referred to in the previous paragraph may travel without a reservation for the purpose of examination, treatment, or care when, for example:
(c) Determining priority for transportation. When the facility director or designee determines there are insufficient resources to transport all persons requesting transportation services, he or she will assist any person denied VTS in identifying and accessing other transportation options. VTS resources will be allocated using the following criteria, which are to be assessed in the context of the totality of the circumstances, so that no one factor is determinative:
(7) The VA facility's ability to maximize the use of available resources.
(The Office of Management and Budget has approved the information collection requirements in this section under control number 2900-0838)
(Authority: 38 U.S.C. 111A, 501)