We are safest on the road when we can see and be seen, day or night. Studies have shown that using low-beam headlights during the day reduces the risk of head-on collisions by over 20%. Automatic daytime running lights help, but don’t illuminate tail lights and should not be confused with headlights, nor should parking lights, which are for parking, not driving. The law requires headlights to be on a half-hour after sunset to a half-hour before sunrise, and whenever snow, rain, or fog limits visibility to less than 500 feet, the best practice is to always drive with low beams on, even in the daytime.
Night driving is more dangerous because the range of your lights limits visibility, and you may risk a collision when you cannot stop within the space you can see. Vermont law requires headlights that illuminate at least 150 feet ahead of a moving vehicle and 200 feet of a vehicle at rest. You should always be able to see at least the distance you will travel in 4 seconds, usually at less than 40 mph with low beams and somewhat faster with high beams, but still slower than safe daytime speeds.
Remember to dim your lights when approaching other vehicles or pedestrians, driving in fog, rain, or snow, and following another vehicle. To avoid being temporarily blinded by an oncoming vehicle, look ahead toward the right edge of the highway until the bright lights have gone by and your vision has returned to normal. This practice will also help you detect bicyclists or pedestrians who may be close to the edge of the road, keeping everyone safer.