What should you do when the headlights fail?

Answer: B — Put on your hazards, slow down, and leave the road.

When headlights fail, you’re less visible to others and your ability to see the road ahead is reduced. The safest move is to quickly alert drivers by turning on the hazard lights, slow down, and, if you can do so safely, pull off the road to a safe area. This keeps you visible and gives you space to stop without blocking traffic. The other options don’t help: high beams won’t restore illumination and can blind others, continuing at normal speed keeps you in a dangerous situation, and simply pulling over with the engine running doesn’t address the lack of visibility and can leave you in a risky spot if you’re not off the roadway yet.