Which of the following lights of a tractor may adversely affect visibility, if they are turned on while driving in fog?
Show the correct answer
Correct answer
A. High-beam lights.
Explanation
In the photo, there is a road covered in thick fog - the trees and posts by the roadway can barely be seen, and further on everything disappears into grey. When you drive a tractor in fog, switched-on main beam headlights can make visibility worse - answer A.
The water droplets that form fog reflect and scatter light. Main beam headlights shine high and far, so instead of lighting the road, they create a bright wall in front of you that dazzles you yourself. That is why the Road Traffic Act requires the driver of a power-driven vehicle in fog to switch on dipped headlights or front fog lights, or both of these lights at the same time. Dipped headlights (answer B) shine low and reflect less off the fog, and front fog lights (answer C) are mounted low and widely light up the edge of the road under the fog - these lights help rather than harm. You may switch on the rear fog lights when visibility drops below 50 m. In fog you exercise particular caution and drive so that you can stop within the visible section of the road.
Legal basis: Art. 30 para. 1 point 1 letter a and para. 3 of the Road Traffic Act (Prawo o ruchu drogowym)