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Transcript: Thursday, November 18, 2004, 1 p.m. ET

Vehicle Lighting

Richard Van Iderstine
Vehicle Lighting Expert, NHTSA
Thursday, November 18, 2004; 1:00 PM

National Highway Traffic Safety Administration (NHTSA) is responsible for reducing deaths, injuries and economic losses resulting from motor vehicle crashes. This is accomplished by setting and enforcing safety performance standards for motor vehicles and motor vehicle equipment. NHTSA also investigates safety defects in motor vehicles, sets and enforces fuel economy standards, helps to reduce the threat of drunk drivers, promotes the use of safety belts, child safety seats and air bags, establishes and enforces vehicle anti-theft regulations and provides consumer information on motor vehicle safety topics.

This discussion was about automotive lighting.

The transcript follows.

Editor's Note: Washingtonpost.com moderators retain editorial control over Live Online discussions and choose the most relevant questions for guests and hosts; guests and hosts can decline to answer questions.


Richard Van Iderstine: Hi! This is Rich. I'm happy to have the opportunity to chat today with you on a subject about which I am passionate: motor vehicle lighting. I was passionate about it even before I came to work at NHTSA. So, please be my guest and ask away.


Houston, Texas: What can be done about the relatively poor performance of headlights provided with the 1998 Plymouth Grand Voyager SE?

Richard Van Iderstine: There can be wide variations in lighting performance from one vehicle to another. Also, some systems will deteriorate with age. To maximize the performance of your headlights, make sure they are kept clean. Dirt reduces the amount of light given off by the bulbs and causes your lights to be more glaring to other drivers. Also, it's important to take your vehicle to a mechanic at least once a year to be sure your headlights are correctly aimed. Lights that are poorly aimed limit your range of vision and can cause other drivers to endure more glare. Also, this vehicle is equipped with a plastic lens that is prone to scratching over time, especially in a sandy environment like you have in Texas. If this is the case with your Plymouth, replacing the headlight unit might help. Remember, too, that your night vision is affected by the cleanliness of your glasses and windshield.


Maryland: The more expensive cars have those fancy blue lights that look cool and really put out a lot of light. I see kits for these things sold in stores and all over the Internet. Is it okay to use these "HID conversion kits?"

Richard Van Iderstine: No, we don't recommend replacing your headlight bulbs with anything other than the type of bulb that was originally used in the car. In fact, it's contrary to federal regulations for these "High Intensity Discharge" (HID) bulb conversion kits to be sold. The reason is that substituting an HID bulb for a halogen bulb will cause a dramatic increase in glare for other drivers.


Bowie, Md.: Why isn't there a standard color for turn signals? Some carmakers go with yellow, while others go with red. With the red, it can get confusing sometimes when someone is braking as most driving decisions are made within seconds.

Richard Van Iderstine: We have studied the crash involvement of vehicles having yellow rear turn signal lights versus red ones. With our data, we have found it challenging to prove that yellow is better than red.


Philadelphia, Penn.: When driving down from Philly to D.C. a few months ago for a conference at night, I noticed almost all of the Maryland State Police vehicles and several DC fire/police vehicles are using new LED lightbars.

As a volunteer firefighter, I'm one of those people who takes notice of these things. I've heard that although they're more expensive, they last much longer and they draw a mere fraction of the energy needed to power traditional lightbars.

Are there any concerns about these super-bright lights on roadways?

Richard Van Iderstine: You may have a legitimate concern. However, regulating emergency lighting is the responsibility of individual states. We do not regulate the additional lighting that is added to emergency vehicles such as fire trucks, police cars, and ambulances. However, we do know that is vitally important that emergency vehicles be highly visible when they are responding to a call.


Virginia: Some vehicles have more than one set of headlights!; This is ridiculous and so bothersome. I hate the glare from these extra lights. Isn't there a law against this?

Richard Van Iderstine: Yes there is. Those "auxiliary" headlights are probably either "fog lights," or a second set of high-beam headlights. These lights are used by drivers to supplement their lower or upper beam headlights. But the fact is that many states restrict how drivers use these auxiliary lights. In most cases, states allow fog lamps to be used only when visibility is reduced by fog, dust, smoke, snow, or rain. Still, surveys done by the University of Michigan's Transportation Research Institute show that most drivers who have fog lamps use them all the time—no matter the weather. This can compound glare problems.


Washington, D.C.: Why is it that many jurisdictions ban the decorative use of neon lights mounted on a car's undercarriage? Is this thought to be a distraction to other drivers?

Richard Van Iderstine: We're not sure why some states ban those lights. Perhaps you should ask your state regulators what the objections are.


Los Angeles, California: I'd like to see the Federal government require that all larger passenger vehicles -- including pickup trucks and SUV's -- have headlights mounted at the same level as passenger cars. I drive an Acura Integra, an average sized two door sedan, and am constantly being blinded while driving after dark by the headlights of oncoming passenger trucks. And when a big SUV is behind me, even the low beams blast my mirrors and make night driving much more stressful and difficult. The headlights of these big gas-hogs are right at the eye level of those of us who drive smaller, more fuel efficient cars. We're already at increased risk of serious injury or death in collisions with these monsters -- do we have to continue to be blinded by them too? This is ridiculous. It seems to me that the manufacturers could easily mount the headlights of SUV's in the bumpers, thus reducing the impact on other motorists and making driving safer for us all.

Michael Taylor

Richard Van Iderstine: Headlamps are currently required to be mounted within a specific range that applies to all vehicle types. However, we are also concerned with the apparent incompatibilities that exist between larger and smaller vehicles on the road today. In fact, we requested comment from the public in 2001 on how to attack this issue in the area of headlamp mounting heights. We are currently reviewing these comments and evaluating possible solutions. You can review the comments that we received at: http://dms.dot.gov in docket number 8885.


Detroit, Michigan: Hi, Richard. As an automotive lighting engineer, I'm concerned about aftermarket replacement rear combination lamps, especially, that don't comply with federal regulations. What are the future plans to control these lamps?

P.S. I also don't like HID glare and would like to see and mandatory leveling system for headlamps.

Richard Van Iderstine: Our enforcement office has conducted numerous investigations related to rear combination lamps in the last several years. The majority of these investigations have resulted in recalls and, in some cases, civil penalties against the importers of these lamps. We plan to continue this effort.

We also are looking at leveling systems as a way to maintain proper headlamp aim.


Worcester, Mass.: Many new cars have switched to "daylight" colored bulbs. Given equal wattage and design parameters, how do they compare to regular halogens in snow or fog. Doesn't the shorter wavelength of the more blue daylight color decrease the ability to see as far as the normal halogens?

Richard Van Iderstine: Those lights on the new cars are the "High Intensity Discharge" (HID) or xenon type of lights. They are used more for their capability to emit light than for their color. The color is really a byproduct of the technology used to achieve the higher performance of the headlights.


Ft. Washington, Md.: A friend of mine keeps bugging me about getting the aim of my headlights changed because I carry so much in the trunk of my car. Is he right?

Richard Van Iderstine: Yes, absolutely, your friend is correct. The load that you place in your vehicle changes headlight aim. The result is that you may not see as well and you may cause glare to other drivers. If you regularly carry a lot of cargo or several passengers, you should make sure that a mechanic adjusts your headlight aim to deal with the angle of your car as you normally load it.


RE: USA: Are you aware of any products/lens/glasses that work to reduce oncoming headlight glare at night?

Richard Van Iderstine: As mentioned in an earlier post, it is very beneficial to keep your headlights, windshield, and eyeglasses clean in order to maximize your ability to see and minimize the effects of glare. Unfortunately, I am not familiar with any other types of products that may help in reducing oncoming headlight glare.


Washington, D.C.: Does Mr. Van Iderstine moonlight as Santa Claus?

Richard Van Iderstine: Yes I do, at my kid's schools and Scout meetings.


Montery, Calif.: Apparently all cars are required to have reflectors on the rear and possibly the sides of the vehicle.

But from observation, it appears that automobiles are NOT required to have 'reflectors' of any kind on the FRONT of the vehicle, although it appears some have white or yellow ones anyway.

Is it true that there is no requirement? Are there any other rules/regulations pertaining to FRONT reflectors?

Please tell me where/how I can find the regulations pertaining to this.

Thank you very much!

Richard Van Iderstine: We do not require front mounted reflectors on motor vehicles. This is because forward illuminating lamps (ie. headlights and fog lights) can provide reflection when illuminated by oncoming headlights.


Washington, D.C.: What about those high-mounted headlights that you see on big vehicles? I personally find them extremely intimidating.

Richard Van Iderstine: High-mounted headlight problems are something we've had since the first time a car encountered a truck, probably in the first part of the 20th Century. For some vehicles, like large trucks, high-mounted headlights are necessary. But for most passenger vehicles, these high-mounted lights are more related to the vehicle's styling than to its function. More SUV's and pickups use high-mounted lights than do cars. Certainly this contributes to more glare problems for drivers in the smaller vehicles. But you can reduce your risk with the use of day/night mirrors and by looking away momentarily when you face the glare. For manufacturers to lower headlights mounted on such light trucks as SUV's and pickups would be challenging, because of the costs of redesign and styling. We are now studying the glare from high-mounted lights and what can be done about it.


Laytonsville, Md.: So what about all these different colored lights that kids -- tuners, I believe they're called -- are putting on their cars. They've got them around their license plates, where their windshield washers jets are, under the sides of the car, inside the passenger compartments. They're just distracting and, I believe, dangerous. What can be done about them?

Richard Van Iderstine: Auxiliary lights that are installed by vehicle owners are not regulated by us. As we mentioned in an earlier post, your state determines what lighting modifications are permitted.


Pinehurst, North Carolina: The driving population today has more elderly drivers with various stages of developing cataracts as well as younger drivers who have had corrective laser surgery. Both of these conditions make the glare of oncoming headlights almost blinding. At the same time halogen headlights in general and the higher position of headlights in SUVs and pickup trucks (an ever increasing number now on the road) are causing difficulty for many drivers, young and old. Is anyone addressing this danger?

Richard Van Iderstine: Yes, as you may see in my other answers, NHTSA is serious about addressing glare issues. But you do bring up a very important point about older drivers who have cataracts. Cataract surgery can often improve vision for drivers and reduce the glare, especially at night.


Alexandria, Va.: A big issue these days is the supposed "excessive glare" from HID's. Recently, I was dumbfounded to learn that an acquaintance drove with his day-night mirror in the "day" position at night. I wonder how common this is, and whether it's the real cause of the glare complaints.

Also, I've found that many automatically-dimming mirrors do not dim enough at night. There's another potential reason.

With the clear safety benefits HID's provide, it would be a shame to ban them without investigating the real causes of complaints against them.

Richard Van Iderstine: Absolutely! You can reduce glare by correctly positioning your rear view mirror for nighttime use. As to your question about HID: I am not aware of any activity that would lead to a ban on HID lights that meet current federal standards.


RE: Daytime running lights: Now that so many vehicles have these, are people forgetting to turn their full lighting systems on at night - taillights, especially? It seems that I notice many more people running without taillights during twilight hours.

Richard Van Iderstine: Yes, I have occasionally seen people drive with only daytime running lights at night. I have done it myself. However, many vehicles, including mine, would not have the instrument panel lit, and drivers would notice that. Also, many vehicles with daytime running lights have headlights that automatically go on at night.


Manassas, Va.: With my '98 Escort, the head lights don't seem to be that bright at night. Sometimes its difficult to see unless I have the brights on. Is it the head light bulbs? or is this type of car normally not a bright head light car? Can something be done to have clearer or brighter lighting at night?

Richard Van Iderstine: In addition to the comments I made earlier about keeping your lights, windshield, and glasses clean, certain headlight lenses may become cloudy over time. If your headlamps have hazed, yellowed, or just appear cloudy, it may be time to replace them.


Richard Van Iderstine: I'm thrilled with the outpouring of enthusiasm and questions on vehicle lighting! It's great to see the variety of inquiries. I hope we can revisit this topic in the coming year. I have really enjoyed the time with you. Thank you vey much!


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