California DMV Permit Test (Class C)Vehicle Operation and MaintenanceMedium

When driving in heavy fog, which of your vehicle's lighting systems should you primarily use to maximize visibility for yourself and other drivers?

  1. ADaytime running lights (DRLs) only.
  2. BParking lights only.
  3. CHigh-beam headlights.
  4. DLow-beam headlights.
Show answer & explanation

Correct answer: D. Low-beam headlights.

Low-beam headlights illuminate the road directly in front of your vehicle without reflecting off the fog and blinding you or oncoming drivers. High-beams reflect intensely off fog, making visibility worse.

Why the other options are wrong

  • A. DRLs are not designed for adverse conditions like heavy fog and do not provide sufficient illumination or visibility.
  • B. Parking lights are not bright enough to illuminate the road or make your vehicle sufficiently visible in heavy fog.
  • C. High-beams reflect off fog particles, creating glare and reducing visibility for everyone.

Driving in Fog

Using specific vehicle controls and techniques to safely navigate low-visibility conditions caused by fog.

  • Use low-beam headlights.
  • Reduce speed significantly.
  • Increase following distance.

Memory trick: Foggy Forecast? Focus Forward, Feet Firm, Fasten Lights.

More Vehicle Operation and Maintenance questions