When a load extends 4 feet or more over the rear of a vehicle during the daytime, what color flag must be attached?

In Texas, when a load extends 4 feet or more over the rear of a vehicle during the daytime, it is required to be flagged with a red flag. This regulation is in place to ensure that other drivers on the road are alerted to the potential hazard posed by an overhanging load. The bright color of the red flag is chosen specifically for its visibility in daylight, helping to effectively signal to other drivers that they should exercise caution and be aware of the extended load. Properly marking the load helps prevent accidents and provides essential awareness on the road.