The Federal Highway Act, referred to in text, is act Nov. 9, 1921, ch. 119, 42 Stat. 212, which enacted sections 1, 2, 3, 3a, 4, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 to 20, 21, 22, 23, 24, and 25 of former Title 23, Highways, and amended sections 5 and 12a of former Title 23 and section 3 of Title 50, War and National Defense. Pub. L. 85–767, Aug. 27, 1958, 72 Stat. 919, repealed the Federal Highway Act, with the exception of the amendment to section 3 of Title 50, as part of the general revision and reenactment of Title 23, Highways.

Act June 29, 1948, ch. 732, § 4(c), 62 Stat. 1105, authorized the appropriation of $6,000,000 for fiscal years 1950 and 1951, respectively, for the carrying out of the provisions of this section.