In United States v. American Trucking Ass'ns, 310 U.S. 534, 543-44, 60 S.Ct. 1059, 1063-64, 84 L.Ed. 1345 (1940), the Court interpreted the Motor Carrier Act of 1935 in light of the Hours of Service Act, the Motor Vehicle Act, the laws governing the Civil Aeronautics Authority, and the subsequently enacted Fair Labor Standards Act. Significantly, the Court in American Trucking was "especially hesitant" to interpret the clause in question in a way that would deviate from the meaning of other related statutes because it was adopted as a floor amendment. See 310 U.S. at 546-47, 60 S.Ct. at 1065-66.