Just pay attention
Although headlights that are on during the daytime might increase some visibility, there are several reasons I do not have DRL's on my cars (or drive with lights on during the day):
1. I drive a motorcycle, and the original purpose of "daytime running lights" was for motorcycles to stand out/stand apart from cars. With cars' lights on all the time, motorcycles no longer stand out. They blend in. Now your cars' lights are a hazard!
2. They increase the cost of replacement parts. Bulbs are not always cheap or easy to replace. Plus there's an additional switch (or more, depending on the vehicle). If you want to drive around with your lights on, there's already a switch for that. Why complicate it by adding another switch? Do you have two switches to turn on your home lights (where you need to 'flip' both to make one light work? No.)
3. When I pull in my driveway at night, I turn my lights off as a courtesy to my neighbors, because my headlights shine directly into their living room/couch. If the lights are on a sensor (some vehicles have this), then as long as the car is running and it's the slightest bit dark,(driving or not), the lights are on.
4. If lights are on all the time, then you can't "signal" to another car if their lights are inadvertently off. Or at a 4 way intersection (if they aren't paying attention).
5. Some people like to have their car started before they drive off (let it warm up in the winter). Theft is now a concern if you can't turn off the lights (especially if it's dark out, now someone knows the car is running for sure!)
6. I have seen it happen, when a car has "DRLs" and they are just barely on, and the driver thinks that their headlights are on, and they drive around. Since the headlights are barely on (some models, mind you), the tail lights are off completely, causing another hazard.
7. If you can't see a regular car, in broad daylight, without their lights on, you don't need a license. There is absolutely no reason to have lights on a semi truck (Daytime lights, during the day).
8. I own the car, and should be able to turn off what I want, when I want. Imagine if this were the attitude towards windshield wipers: "Let's have the wipers on all the time, just in case there's any dirt or something on the windshield".. How stupid is that? I don't need someone else telling me that I need to have lights on during the day.
9. This might sound far fetched, but honestly, there used to be some pride in having your lights on when driving in a funeral procession. Call me old fashioned, but if you see a string of cars with all their lights on, it used to be a significant display of honor.
10. Some cars' DRLs are the bright lights, at 50%. When that car comes up over a hill, the glare is temporarily blinding (because of the angle of the light). This also may indicate that an oncoming car appears further than it really is (an illusion of depth), thus giving the person that is about to pull out, less time, and possibly cause an accident.
One time, someone argued with me, by saying "well, if my lights are on during the daytime, you can see my car from two miles away".. I laughed at them and said: "so you'd rather someone pay attention, (get distracted) by a car that's two miles away, instead of the cars directly in their vicinity.
Now by all means, if you think you need your car's headlights on, when there's a huge ball of fire in the sky, illuminating half of the entire Earth all at one time, then by all means, drive around with your lights on.
Plus, if it were really safer, don't you think they'd require any race cars to have "running lights" of some sort? I don't see DRLs on NASCAR, do you? It's not like headlights are made of glass very often (Jeep/Hummer I think still have actual glass), so you can't say that's an issue.
From what I read on the "studies", many of them appear to be biased, or flawed at best. I don't see how forcing a driver to have their lights on ALL THE TIME, will have more positive impacts, then negative ones. I listed TEN issues I have with them, and there's only "one" positive impact of having DRLs on a car, and that's the POSSIBILITY of an increase in reaction time; which has never been actually proven. So although there are people that will argue this until the end of time, I find that putting the lives of every motorcyclist in danger is far too costly for a "chance" that you "could" eliminate an automobile collision. People simply need to pay attention, and there's absolutely no gimmick on a car that will replace that. That's an absolute fact. Until every vehicle is completely automated, you will never eliminate human error. Having DRLs on your car is a hazard, no matter how you argue it.
I personally think it's stupid to have lights on during the day. So because I see so many cars with their lights on during the daytime, I've upped my motorcycles lights to 35W HID 8000K. I'm thinking of upping them to 55W HID 8000k, so I stand out even more. I wouldn't have to do this, if there weren't so many cars with lights on. I also drive with my brights on during the day (on my motorcycle, of course).
No, sorry this is wrong. Headlights of any type on cars coming towards you increase their relative visibility compared to the background. There are LOTS of studies on the effectiveness of DRLs on cars.
http://www.ibiblio.org/rdu/DRLs/studies.htm
