Final answer:
Carriers in the United States must keep log books, which are part of the Records of Duty Status (RODS), for a period of six months to comply with the Federal Motor Carrier Safety Administration regulations.
Step-by-step explanation:
The requirement for carriers to keep log books is a regulation that falls under the Federal Motor Carrier Safety Administration (FMCSA). In the United States, carriers are required to retain Records of Duty Status (RODS), which include log books, for a period of six months. These records are essential for ensuring compliance with Hours of Service (HOS) regulations, which are intended to prevent driver fatigue and promote safer driving conditions.
It is crucial for carriers to understand this regulation to avoid potential penalties and to ensure the safety and well-being of their drivers. Failure to retain log books for the required duration can result in fines and other legal complications.