108 STAT. 848 PUBLIC LAW 103-272—JULY 5, 1994 section, is a contractual obligation of the United States Government to pay the Government's share of the cost of the project. (2) A grant or contract, approved by the Secretary, that is financed with amounts made available under subsection (a)(2) or (b)(2) of this section, is a contractual obligation of the Government to pay the Government's share of the cost of the project only to the extent amounts are provided in advance in an appropriations law. (1) EARLY APPROPRIATIONS AND AVAILABILITY OF AMOUNTS. — (1) Amounts appropriated under subsection (a)(2) of this section to carry out section 5311 of this title may be appropriated in the fiscal year before the fiscal year in which the appropriation is available for obligation. (2) Amounts made available or appropriated under subsections (a), (b), (g), (h)(1) and (2), and (j)(4) of this section remain available until expended. (3) An amount apportioned under section 5308 of this title— (A) remains available for 3 years after the fiscal year in which the amount is apportioned; and (B) that is unobligated at the end of the 3-year period shall be added to the amount available for apportionment for the next fiscal year not later than 30 days after the end of the 3-year period. CHAPTER 55—INTERMODAL TRANSPORTATION SUBCHAPTER I—GENERAL Sec. 5501. National Intermodal Transportation System policy. 5502. Intermodal Transportation Advisory Board. 5503. Office of Intermoaalism. 5504. Model Intermodal transportation plans. SUBCHAPTER II—TERMINALS 5561. Definition. 5562. Assistance projects. 5563. Conversion of certain rail passenger terminals. 5564. Interim preservation of certain r£l passenger terminals. 5565. Encouraging the development of plans for converting certain rail passenger terminals. 5566. Records and audits. 5567. Preference for preserving buildings of historic or architectural significance. 5568. Authorization of appropnations. SUBCHAPTER I—GENERAL § 5501. National Intermodal Transportation System policy (a) GENERAL.—It is the policy of the United States Government to develop a National Intermodal Transportation System that is economically efficient and environmentally sound, provides the foundation for the United States to compete in the global economy, and will move individuals and property in an energy efficient way. (b) SYSTEM CHARACTERISTICS.— (1) The National Intermodal Transportation System shall consist of all forms of transportation in a unified, interconnected manner, including the transportation systems of the future, to reduce energy consumption and air pollution while promoting economic development and supporting the United States' preeminent position in international commerce. (2) The National Intermodal Transportation System shall include a National Highway System consisting of the Dwight D.