Notwithstanding any other provision of law, where the National Park Service or an entity under a service contract, cooperative agreement, or other contractual arrangement with the National Park Service provides transportation to all or a portion of any unit of the National Park System, the Secretary may impose a reasonable and appropriate charge to the public for the use of such transportation services in addition to any admission fee required to be paid. Collection of both the transportation and admission fees may occur at the transportation staging area or any other reasonably convenient location determined by the Secretary. The Secretary may enter into agreements with public or private entities, who qualify to the Secretary’s satisfaction, to collect the transportation and admission fee. Such transportation fees collected as per this section shall be retained by the unit of the National Park System at which the transportation fee was collected and the amount retained shall be expended only for costs associated with the transportation systems at the unit where the charge was imposed.