Sec. 4(i) of the Department of Transportation Act, 49 U.S.C. 5561-5568, as amended by (1) sec. 15 of the Amtrak Improvement Act of 1974, Public Law 93-496, 88 Stat. 1528; (2) sec. 13 of the Amtrak Improvement Act of 1975, Public Law 94-25, 89 Stat. 93; (3) sec. 706 of the Railroad Revitalization and Regulatory Reform Act of 1976, Publaw Law 94-210, 90 Stat. 125; and (4) sec. 219(a) of the Rail Transportation Improvement Act, Public Law 94-555, 90 Stat. 2629; and regulations of the Office of the Secretary of Transportation, 49 CFR 1.49(r).