Car headlights aren’t just for nighttime driving. Did you know that most states legally require you to use your headlines during the day under certain circumstances?
While the specific laws vary by state, you will need your headlights during the day if:
Visibility is low because of bad driving weather conditions like fog, rain, or snow
You’re driving through a narrow mountain pass
You’re on winding roads
You’re driving through a construction zone
Interestingly, whole countries now require daytime running lights that remain on the entire time your vehicle is running. The U.S. isn’t one of those countries yet, but we could be in the future.
But why?
If you can see perfectly fine, why would you need to use your headlights? Let’s shed some light on this driver safety topic (pun absolutely intended).
State Laws Regarding Daytime Headlight Use for Bad Weather
Lots of states have laws requiring you to turn on your headlights during the day if visibility is less than 500 feet or 1,000 feet. This is obviously meant to help you see better so you can avoid a collision. However, since most people probably can't identify just how far their visibility is on a whim, a general rule is to just turn on your lights to be safe.
Around 20 states, including New York and California, require you to have your headlights on if your windshield wipers are on. This makes sense because your wipers would only be on if it’s actively raining, sleeting, or snowing. Since those conditions all lower visibility, turning on your headlights will help you see better.
Be sure to check your local headlight laws so you know what’s legally required in your state.
Daytime Headlight Use — The Not-So-Obvious Reasons
Ok, so weather and visibility make sense, but why would you need headlights on mountain roads or in construction zones? The answer: so other people can see you! Headlights aren’t just about helping you see better. They’re about making you more visible to other people.
On those narrow mountain roads, cars can blend into the mountains in the background. With lights on, they stand out better to other drivers. Same with winding mountain roads. Even during the daylight, you can usually see headlights from a car coming around a blind bend. This will give you an advanced warning that a car is coming before you ever see the car.
This is why you’ll often see road signs in mountainous states saying something like “daytime headlight use required for the next 10 miles.” California specifically requires daytime headlight use on mountain roads.
This is the same principle behind Pennsylvania’s law requiring daytime headlight use in construction zones. Yes, it’s to make sure you, as the driver, can see as well as possible, but it’s also to help workers see you.
What About Daytime Running Lights?
If daytime headlights make us more visible, should we all have them on all the time? Canada, Norway, Denmark, the UK, and several other countries think so. They made daytime running headlights mandatory on all vehicles.
In the U.S., this isn’t currently a requirement. But data suggests that maybe it should be. The National Highway Traffic Safety Administration (NHTSA) found that daytime headlights use reduced daytime crashes from light trucks and vans by 5.7%.
See and Be Seen on the Road
Safe driving is about seeing and being seen to avoid collisions. Daytime headlights help you do both. So whether you’re a new driver-in-training or an experienced driver who practices defensive driving to stay safe, turn on those headlights, even during the day.
