In what circumstances should you flash your headlamps to other road users?

You should flash your headlamps to other road users to alert them of potential hazards, such as when they are driving inappropriately or if you need to signal your presence in low visibility conditions. It's also appropriate to flash your headlights to thank another driver for yielding the right of way or to indicate that it is safe to merge. However, avoid excessive flashing, as it can be distracting or misinterpreted. Always prioritize safety and ensure that your actions do not create confusion on the road.