Headlights in daytime - why?

After a recent drive to the beach (thru Maryland & Delaware) I gotta vent about this. What’s the deal with car headlights on in the daytime (on a clear, sunny day)? On my recent drive, I noticed road signs saying “Use of headlights suggested.” I commented (loudly) to my friend “If someone can’t see me in the daytime without my headlights on, they’re blind and shouldn’t be driving!” Hey, how about signs saying “Use of courtesy suggested,” or better yet, “Use of turn signals suggested.” Someone told me that now all new cars are being made so that the headlights come on when you turn on the ignition. I can’t stand it. As far as I know, there’s no law requiring headlights in daytime, yet the auto manufacturers are going to force us to do this. If I get a new car, I will have that feature disabled.

Why? Do ya wanna sneak up on somebody?

All the headlights do is make it just a little bit easier for other people to see you coming. Motorcycles have had the manditory running headlights for decades. It isn’t a conspiracy between automakers and the Halogyn industry, it’s just another pasive safety feature that doesn’t demand anything from you. Unless you object to them on asthetic grounds, well then have at it.

If you want something really worth ranting about, how about headlights on vacumn cleaners?

In Scadinavia headlights have been mandatory during daylight for at least 15 years. Car with headlights on is much easier to see even when sun is behind it.
Varying light conditions, ie on the highway, sort of makes car with lights on much safer and more visible.

Cogito Ergo Vroom
I think therefore I ride fast…

I don’t know it for a fact, but I have heard that driving with your headlights on during the day has been shown statistically significant in reducing accidents. There’s a daytime headlights test area a ways north of here, and I have heard, again anecdotally, that when it went in to effect the accident rate lowered on that stretch of highway.


I’m a woman phenomenally
Phenomenal woman
That’s me
(Maya Angelou)

The NTSB demonstrated that lights reduce accidents significantly on two-lane roads as long ago as 1971. There have been two brief attempts to put always-on running lights on cars. The first was voluntary and fizzled, the second was to be mandated and was killed incommittee. (You don’t need headlights, just some sort of light to indicate that the car is approaching, not receding.)

In the two-lane road scenarios, people are much less likely to attempt to pass when they see lights indicating a car in the oncoming lane and people are much less likely to pull out in front of a light-identified car.

On freeways, I suspect that there may be some reduction of accidents due to better recognition of people (lights) in the mirrors, (way too many fools out there driving as though they don’t need to know who’s behind them), but the big payback was on two-lane roads.


I suspect the two-lane passing scenario Tom described is because with two points of light to use as a reference (binocular advantage, so to speak) people can more easily and accurately judge the speed and distance of an approaching vehicle.

I always run with headlights when driving for extended lengths of time, such as interstate driving. I figure what the hell, maybe that dope who’s falling asleep in the left lane will perk up and think I’m a cop coming upon him at 80 mph and get the frig out of my way. Then I leave my lights on at my destination and curse the fact my car does not have daytime running lights.

The headlight on my vacuum cleaner has definitely reduced the housepet/cleaner accident statistics in my house alone. For that alone, my dog is eternally grateful.

“…send lawyers, guns, and money…”

 Warren Zevon

well we all have our pet peeves – I don’t why this has bugged me so much, but it has, but you just about have me convinced it’s a good thing. It’s just seems like an easy out when there are other things (like road rage and signalling) that seem to me to be more important but don’t have such a simple solution. Thanks for the input guys.

posted 06-10-99 09:25 PM


Unless you object to them on asthetic grounds, well then have at it.

You hit it right on the nose there. My car ('96 Chevy Corsica) has DRL’s that look absolutly stupid. One way to disable the DRL’s is to leave the parking brake on just one click. It doesn’t affect driving, but it keeps the lights off.

I’m with Tom on the two-lane situation. One additional points: there are lots of cars that are silver or grey colored, that are very difficult to see in the distance. The headlights help.

Though I was flummoxed when I first rented a car with daytime running lights (I can’t get the lights off! The battery’s gonna die!) I have to admit that I like them now. If you need a selfish reason to use them, I’ve noticed cars getting out of my way when they see the lights on - apparently they think there is some emergency or I’m part of a funeral procession :slight_smile:

My own pet peeve is suicidal drivers who don’t put on the lights in parking garages. Yoo-hoo, it’s dark in there, and it’s especially dark when you enter them from the bright sunlight.

My pet peeve are people in low visibility conditions or in dusk/dawn time frames that refuse to turn their lights on.

I can just imagine them thinking “I don’t need my lights on, I can see just fine!”

I would really love to be able to pull them over and point out to them that by turning their lights on, they will be more visible to others, and possibly prevent some other non-driving idiot on the road from running onto them.

End of Rant.


ExTank - Your first task would be to convince them that there actually are others on the road.

The overwhelming majority of people have more than the average (mean) number of legs. – E. Grebenik

Felinecare did say:

My own pet peeve is suicidal drivers who don’t put on the lights in parking garages. Yoo-hoo, it’s dark in there, and it’s especially dark when you enter them from the bright sunlight.

This is a friend-of-a-friend report, but years ago I was told that someone’s insurance company only paid off part of their accident claim, because the company said driving in a parking garage without their headlights on contributed to the accident.

it’s for your saftey…

PapaBear writes:

Is there evidence that this is not like sticking one of those Day-Glo orange ping-pong balls on your car’s radio antenna to make it easier to find; i.e., that it works until everybody does it, at which point we all ignore it?

“Gold cannot always get you good soldiers, but good soldiers can always get you gold”

Not really. They do the same thing on the railroads, where locomotives have run with lights in the daylight for years. A visible light says more that “object ahead.” A visible light says “object ahead, in motion, aimed at you.”

Would there be some diminishing effect on freeways where, in moderate to heavy traffic, any single set of lights in your rearview mirror would be mentally dismissed as “just one more car”? Very possibly. Would there ever be a time when someone on U.S. 2 in Montana would fail to notice that there was an oncoming car in the heat waves? Unlikely.
There will, indeed, be people who will see the lights and still cause an accident trying to pass another car because they will judge the distance badly, but that simply reflects a general lack of judgment among a certain percentage of drivers.


I asked this question a few months back, should still be in the archives.

On My car, Grand Am SE, The headlights are always on, Well Daytime running lamps at day and headlights at night. It has a sensor and just does it for me, even at night I can’t turn them off if I want to (unless I park the car and pull the E-brake, or turn off the engine. You said that the sign suggested head light use on the way to the beach. Do you mean just while you were on the drive there or, when you were close to the beach (ie pulllng up to the sand to park), in which case maybe it has a history of a land of sand flying up in the air and making it hard for other people to see your car

Formerly known as Nec3f on the AOL SDMB


Actually, I would think things would get even better when everyone was following daytime light usage. Then you’d be better trained to think “car with lights”=“moving car”, “car with no lights”=“stopped car”. Until then, “car with no lights” might= “stopped car” but then again it might not.