While driving a truck, when must you switch from high-beam to low-beam lights?
Show the correct answer
Correct answer
B. Always when there is a possibility of blinding the driver of the vehicle in front of you.
Explanation
In the picture you can see the main beam symbol (blue) with an arrow leading to the dipped headlights symbol (green) - that is, switching the lights. You must switch from main beam to dipped headlights whenever there is a possibility of dazzling the driver of the vehicle in front - answer B.
The Road Traffic Act allows you to use main beam from dusk to dawn on unlit roads, as long as you do not dazzle other drivers or pedestrians walking in a column. You must switch them to dipped headlights, among other situations, when approaching a vehicle in front, if its driver may be dazzled. The mere fact that you can see a vehicle in front of you (answer A) is not yet enough - if the vehicle is far ahead of you, your lights will not dazzle its driver through the mirrors. A single pedestrian (answer C) is not mentioned in the rule at all; it only mentions pedestrians walking in a column. In a lorry the headlights are high up, so you switch to dipped headlights suitably early when there is a passenger car in front of you.
Legal basis: Art. 51 para. 3 point 2 of the Road Traffic Act (Prawo o ruchu drogowym)