Final answer:
In the event a driver is about to be rear-ended, they should maintain their position, ensure seat belts are fastened, headrests are properly adjusted, and let the other driver handle the incident.
Step-by-step explanation:
If a driver is about to be struck from the rear by another vehicle, the best course of action is to maintain your position and let the other driver handle the situation. Signaling the other driver to move to another lane or flashing your headlights could be misinterpreted and might not prevent the collision. Honking your horn could alert the driver in front, but depending on the situation, it might not provide them with enough time to react appropriately. It's important to stay alert and prepare for the impact by ensuring you are wearing your seatbelt and your headrest is properly adjusted to minimize potential injuries.