Final answer:
High-beam headlights must project at least 350 feet down the road to ensure visibility of potential hazards and obstacles.
Step-by-step explanation:
The distance that high-beam headlights must project down the road depends on various factors such as the type of vehicle and road conditions. However, a common recommendation is for high-beam headlights to project light at least 350 feet down the road. This allows drivers to see potential hazards and obstacles in advance.