Final answer:
To mark a load that projects 4 ft or more to the rear of the vehicle, use a red flag or red lights to increase visibility and ensure safety.
Step-by-step explanation:
How to mark a load that projects 4 ft or more to the rear of the vehicle:
When driving a vehicle with a load that extends 4 ft or more to the rear, it is important to mark the load to ensure safety. In most states, you are required to use a red flag or red lights to mark the end of the load. You can also use reflective tape or signs to increase visibility.
For example, if you are transporting a long ladder that extends beyond 4 ft from the rear of your vehicle, you would attach a red flag to the end of the ladder or use red lights that are visible from the rear. This helps other drivers to see the load and take necessary precautions.