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 drawing you can see the main beam symbol (blue) with an arrow leading to the dipped headlights symbol (green). 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 requires a driver using main beam headlights to switch to dipped headlights when approaching a vehicle in front, if its driver could be dazzled, and also when a vehicle is approaching from the opposite direction. The mere fact that you see a vehicle ahead of you (answer A) is not enough - if it is far away, your lights will not dazzle its driver. The rule does not mention a single pedestrian (answer C): it speaks of not dazzling pedestrians walking in a column. In a bus the headlamps are mounted high, so the light easily hits the mirrors of the vehicle in front of you - you switch them with a good margin of distance.
Legal basis: Art. 51 para. 3 point 2 of the Road Traffic Act (Prawo o ruchu drogowym)