In the case of United States et al. v. Rock Island Motor Transit Co. et al., 1950, the U.S Supreme Court was tasked with deciding whether or not a railroad company could legally own and operate a trucking business under existing federal law at that time (the Interstate Commerce Act). The Rock Island Motor Transit Company was owned by the Chicago, Rock Island & Pacific Railroad Company and operated as an interstate motor carrier service in several states across America's Midwest region. The government argued that this arrangement violated Section 5(4) of the Interstate Commerce Act which prohibited railroads from acquiring control over competing forms of transportation without approval from the Interstate Commerce Commission (ICC). However, on appeal to the Supreme Court, it ruled in favor of Rock Island stating that Congress did not intend for section 5(4) to apply to situations where railroads acquired control over motor carriers before enactment of this provision in 1940.

The dissenting opinion in the United States v. Rock Island Motor Transit Co. case argued that the Interstate Commerce Commission (ICC) should have jurisdiction over interstate motor carriers, even if they are owned by a railroad company and operate as part of its service. The dissenters believed that Congress intended for all interstate motor transportation to be regulated by the ICC when it passed the Motor Carrier Act of 1935, regardless of who owns or operates them. They also pointed out that exempting these types of companies from regulation could lead to unfair competition and other problems in the industry. Therefore, they disagreed with majority's decision which held otherwise.