Section, added Pub. L. 93–643, § 122(a), Jan. 4, 1975, 88 Stat. 2289; amended Pub. L. 94–280, title I, § 135(a), May 5, 1976, 90 Stat. 441; Pub. L. 95–599, title I, § 168(d), Nov. 6, 1978, 92 Stat. 2723; Pub. L. 96–106, § 10(a), Nov. 9, 1979, 93 Stat. 798, related to projects for safer off-system roads.