Under what condition does a driver require a log?

The requirement for a driver to maintain a log, particularly in the context of commercial driving regulations, is primarily linked to hours of service. When a driver exceeds 12 hours of driving without returning to their starting location, they must have a log to document their driving hours, breaks, and rest periods. This is crucial for ensuring compliance with regulations that prevent driver fatigue and promote safety on the road.

Maintaining a log allows for accurate tracking of driving time and ensures that drivers take necessary breaks to rest, which is essential in preventing accidents caused by fatigue. This condition serves as a framework to protect both the driver and the public by enforcing limits on continuous driving hours.

In contrast, feeling fatigued may indicate a need for a break, but it does not automatically necessitate a log. Similarly, driving over 50 miles does not inherently trigger the requirement for a log, as the key factor is the duration of driving time beyond 12 hours without returning to the starting location. Lastly, while law enforcement can request a log, this is not a condition that independently requires one to be kept.