Which regulatory body oversees transportation compliance in the U.S.?

The Federal Motor Carrier Safety Administration (FMCSA) is tasked with overseeing transportation compliance specifically related to the commercial motor vehicle industry in the United States. This includes regulating the safety of commercial drivers, ensuring vehicles meet safety standards, and enforcing compliance with federal regulations that govern the operation of large trucks and buses.

The FMCSA's primary mission is to reduce crashes, injuries, and fatalities involving large commercial vehicles. By establishing and enforcing regulations that pertain to vehicle maintenance, driver qualifications, and operational safety, the FMCSA plays a critical role in promoting safe transportation practices.

While other agencies mentioned focus on different aspects of transportation — the FAA oversees aviation safety, NHTSA regulates vehicle safety standards and recalls, and the DOT encompasses all transportation sectors — the FMCSA specifically focuses on the commercial motor carrier sector and its unique compliance needs. This specialization makes the FMCSA the correct answer for the question regarding oversight of transportation compliance in the U.S.