When is a "log book" required for commercial drivers?

A "log book," also known as a driver's daily log or hours of service log, is required for commercial drivers primarily to ensure compliance with federal regulations regarding driving hours and rest periods. The requirement for a log book comes into play when a driver operates a commercial vehicle under specific conditions.

When a driver is operating a vehicle requiring a Commercial Driver's License (CDL) or when traveling more than 100 air miles from the base or terminal, maintaining a log book becomes necessary. This helps monitor the driver's hours and ensures they are not exceeding the maximum driving time allowed by law, promoting safety on the road.

This requirement is crucial for preventing fatigue and ensuring that drivers take adequate rest, which is important in reducing the risk of accidents. Log books provide a record that can be reviewed by law enforcement and regulatory agencies to ensure compliance with these safety regulations.

In contrast, the other scenarios either do not address the regulatory need to maintain accurate records for longer trips or misrepresent the conditions under which a log book is mandated.