Final answer:
Visual warning devices should typically be visible for at least 100 meters in both directions when a vehicle has broken down, ensuring that oncoming traffic can respond safely.
Step-by-step explanation:
The required visibility distance for visual warning devices when a vehicle has broken down. The correct visibility distance that visual warning devices, such as flares, reflective triangles, or cones, should be visible on the road in both directions for safety purposes varies depending on local laws and regulations. However, a commonly followed guideline is that such devices should be visible for at least 100 meters (approximately 328 feet) in both directions. This ensures that oncoming traffic has sufficient distance to see the warning signs and slow down or stop safely. To ensure safety when placing warning signals, always consider the speed at which vehicles are traveling, road conditions, and visibility.