When lights are required, drivers are required to switch to low beam headlights…?
- Within 150 metres of an oncoming vehicle ✓
- Within 1 KM of an oncoming vehicle
- If they choose to
- Within 300m of an oncoming vehicle
Answer: A. Within 150 metres of an oncoming vehicle
When lights are required, you must switch to low beam headlights within 150 metres of an oncoming vehicle, so the correct choice is the 150 metres one.
Why this is the answer
The handbook says you must dim your high beams when you are within 150 metres of another vehicle, whether you are meeting it or following it. It also tells you that most people misjudge distance, so it recommends dimming early to be courteous. The requirement applies to oncoming traffic, so the 150-metre figure is the one that matches the rule. Nothing in the passages describes any longer distance for meeting an approaching vehicle.
Why the other answers are wrong
- B. Within 1 KM of an oncoming vehicle — The handbook gives 150 metres as the dimming distance for another vehicle, not a full kilometre, so this is far too long.
- C. If they choose to — Dimming is stated as something you must do, not something you decide at will.
- D. Within 300m of an oncoming vehicle — The passage names 150 metres for approaching or following another vehicle, so 300 metres is not the figure given.
Remember it
Picture a 150-metre gap: dim your high beams before you close that distance, because judging distance by eye is harder than it feels.