What light beam should be used when driving at night in heavy fog?

Using low beam headlights while driving at night in heavy fog is the recommended approach because they help improve visibility without causing excessive glare. High beam headlights can reflect off the fog, rain, or snow, and create a wall of light that can make it even more difficult to see. In contrast, low beam headlights emit a softer light that penetrates the fog better and reduces glare, allowing you to see the road and surrounding area more clearly.

Fog lights alone can be useful, but they are designed primarily for use in conjunction with low beams rather than as a standalone light source for nighttime driving. Additionally, using flashers can be confusing to other drivers and is not designed for illuminating the roadway. Therefore, the use of low beam headlights serves the safest and most effective way to navigate through foggy conditions.