Section 61, acts Mar. 4, 1907, ch. 2939, Sec. 1, 34 Stat. 1415; Dec. 26, 1969, Pub. L. 91-169, Sec. 1, 83 Stat. 463; July 8, 1976, Pub. L. 94-348, Sec. 4(c), 90 Stat. 818; Nov. 2, 1978, Pub. L. 95-574, Sec. 5, 6, 92 Stat. 2461; June 22, 1988, Pub. L. 100-342, Sec. 16(1), 102 Stat. 634, provided that this chapter applied to any railroad and defined ''railroad'', ''employee'', ''time on duty'', and ''designated terminal'' for purposes of this chapter. See sections 20102, 21101, and 21103 of Title 49, Transportation.

Section 62, acts Mar. 4, 1907, ch. 2939, Sec. 2, 34 Stat. 1416; Oct. 15, 1966, Pub. L. 89-670, Sec. 6(e)(2), 80 Stat. 939; Dec. 26, 1969, Pub. L. 91-169, Sec. 1, 83 Stat. 463; July 8, 1976, Pub. L. 94-348, Sec. 4(a), (b), 90 Stat. 818; June 22, 1988, Pub. L. 100-342, Sec. 16(2), 19(b)(1), 102 Stat. 634, 638, related to limitations on employees' hours of service, determination of number of hours an employee is on duty, additional duty for crew of wreck or relief trains during emergencies, and inapplicability of this section when provisions of section 63 of this title applied, and defined ''employees'' for purpose of subsec. (a)(3) of this section. See sections 21103, 21105, and 21106 of Title 49.

Section 63, acts Mar. 4, 1907, ch. 2939, Sec. 3, 34 Stat. 1416; May 4, 1916, ch. 109, Sec. 1, 39 Stat. 61; Aug. 14, 1957, Pub. L. 85-135, Sec. 2, 71 Stat. 352; Oct. 15, 1966, Pub. L. 89-670, Sec. 6(e)(2), 80 Stat. 939; Dec. 26, 1969, Pub. L. 91-169, Sec. 1, 83 Stat. 464; June 22, 1988, Pub. L. 100-342, Sec. 16(3), 102 Stat. 635, related to dispatchers' hours of service. See section 21105 of Title 49.

Section 63a, acts Mar. 4, 1907, ch. 2939, Sec. 3A, as added July 8, 1976, Pub. L. 94-348, Sec. 4(d), 90 Stat. 819; amended Nov. 2, 1978, Pub. L. 95-574, Sec. 4(a), (b), 92 Stat. 2459, 2460; June 22, 1988, Pub. L. 100-342, Sec. 16(4), 102 Stat. 635, related to signal system employees' hours of service. See sections 21102, 21104 to 21107, and 21303 of Title 49.

Section 64, acts Mar. 4, 1907, ch. 2939, Sec. 4, 34 Stat. 1417; Oct. 15, 1966, Pub. L. 89-670, Sec. 6(e)(2), 80 Stat. 939; Dec. 26, 1969, Pub. L. 91-169, Sec. 1, 83 Stat. 464; June 22, 1988, Pub. L. 100-342, Sec. 16(5), 102 Stat. 635, provided that time on duty requirements of this chapter were maximum permissible hours of service, but shorter periods were proper subjects for collective bargaining. See section 21107 of Title 49.

Section 64a, acts Mar. 4, 1907, ch. 2939, Sec. 5, 34 Stat. 1417; Dec. 26, 1969, Pub. L. 91-169, Sec. 1, 83 Stat. 464; July 8, 1976, Pub. L. 94-348, Sec. 4(e), 90 Stat. 819; Oct. 10, 1980, Pub. L. 96-423, Sec. 12, 94 Stat. 1816; June 22, 1988, Pub. L. 100-342, Sec. 16(6), 102 Stat. 635; Sept. 3, 1992, Pub. L. 102-365, Sec. 4(a)(2), (c)(2), 9(a)(2), 106 Stat. 973, 974, 977, related to manner of enforcing this chapter concerning hours of service of employees. See sections 21102, 21303, and 21304 of Title 49.

Section 64b, act Mar. 4, 1907, ch. 2939, Sec. 6, as added Dec. 26, 1969, Pub. L. 91-169, Sec. 1, 83 Stat. 465, provided that Secretary of Transportation was to have duty to carry out provisions of this chapter

Act Mar. 4, 1907, ch. 2939, 34 Stat. 1415, which enacted this chapter and which was repealed by Pub. L. 103-272, Sec. 7(b), July 5, 1994, 108 Stat. 1379, was popularly known as the ''Hours of Service Act''