What should be done when a trailer's weight exceeds 5 feet from the rear of a vehicle?

When a trailer's weight extends beyond 5 feet from the rear of a vehicle, it is essential to mark that extension for safety visibility. The correct procedure is to mark the end of this extension with a red flag during daylight hours. This requirement is in place to alert other drivers to the potential hazard, as anything extending beyond the standard profile of a vehicle may not be easily visible, especially to vehicles following behind.

Using a red flag is a common safety protocol, universally recognized by drivers as a warning signal. The prominence of the color red draws attention and helps ensure that other road users are aware of the trailer's extended length. This marking is crucial not only for compliance with traffic regulations but also for preventing accidents by informing drivers about the size and shape of the vehicle they are following.

The other options do not meet the requirements for safely signaling an extended load. A yellow flag is not the standard for this situation, and using a blue light at night does not provide the visibility needed for trailing vehicles. Coast to a stop, while safe in some contexts, does not address the need for active warning during transport and could lead to unsafe driving conditions if sudden stops occur. Thus, marking with a red flag is the most appropriate and effective measure to take when