According to FSS 316.228, what is the size requirement for the red flag displayed when a load extends more than 4 feet?

The correct answer is that the red flag must be a minimum size of 18 inches square when a load extends more than 4 feet beyond the vehicle. This requirement is established to ensure visibility and safety for both the driver of the vehicle carrying the load and other road users. A flag of this size is more likely to be seen by others from various distances and angles, helping to alert them to the presence of an extending load.

The use of clear and standardized dimensions for flags helps maintain consistency across different vehicles and types of loads, ensuring that all road users are aware of potential hazards. Adhering to these requirements is essential in promoting safety on the roads, which is the overarching goal of such regulations.