For increased visibility in adverse weather conditions, your vehicle's headlights should be set to:

Using low beams for increased visibility in adverse weather conditions is essential because they produce a wider and more controlled illumination without creating glare that can reflect off rain, fog, or snow. High beams can actually impair visibility in such conditions; the light can bounce back, causing a blinding effect, which can make it difficult to see the road ahead clearly. Parking lights are insufficient for driving as they do not provide adequate illumination for visibility on the road. Emergency lights are intended for signaling others and should not be used when driving in adverse conditions, as they do not assist with seeing the roadway. Therefore, utilizing low beams is the safest and most effective choice for enhancing visibility when facing rain, fog, or snow.