What is the purpose of the "log book" for commercial drivers?

The "log book" for commercial drivers serves the critical function of tracking driving hours, breaks, and off-duty time. This tool is essential for compliance with federal regulations, specifically those set by the Federal Motor Carrier Safety Administration (FMCSA), which aim to ensure that drivers do not exceed the maximum driving limits and take adequate rest periods. Properly maintaining a log book helps prevent fatigue-related accidents by ensuring that drivers have recorded their hours accurately and are adhering to the mandated rest requirements. By monitoring these elements, drivers can maintain safe driving practices, ensure their own well-being, and comply with legal responsibilities. This plays a significant role in promoting road safety for all users. Other options, while they may pertain to aspects of vehicle operation, do not align with the primary purpose of the log book regarding driving hours and safety regulations.