Growing up in central New York near Ithaca in the 1960’s, I was part of a large middle class family consisting of six kids and my mom and dad. We lived what I think is a simpler life, without cable TV or a 24-hour grocery store. We traveled to Ithaca to shop for clothing and related items, and we seldom went out to eat with the exception of an occasional pizza from the local pizza shop.
Times have really changed. We now have the option to shop at stores whenever we have a few spare minutes, and the open-24/7 stores offer many more services than those did during my simple times growing up. The bottom line: we are making more trips at all hours of the day than we did over four decades ago. We are traveling without regard to the dangers of driving at night. We need better quality headlights for our vehicles than we have had in the past.
As our need to drive more at night has increased, the idea of what constitutes a quality forward lighting systems has changed as well. Our need for uniformly spread headlamp beam with enough seeing distance to see down the road has become increasingly important. The University of Michigan Transportation Research Institute (UMTRI) has studied the low beam pattern of many headlamps on the road today and discovered something very interesting: many of today’s low beam headlamps only have enough “reach” to provide emergency stops (with some safety margin) if you are driving less than 45 miles per hour. Driving any faster than 45 mph may allow you to detect targets in the road but they do not have sufficient stopping distance to stop the vehicle before hitting them.
As the largest population segment (the baby boomers) gets older and nears retirement age, we have seen an increasing number of complaints about glare. As a matter of fact, in 2001 the National Highway Traffic Safety Administration issued a request for comment on the glare experience of the public, and they received more comments on this issue than any other topic. Glare is present in two varying levels: discomfort glare and disability glare, and the volume of complaints is increasing. Discomfort glare is simply the expression of glare that is painful to look at, while disability glare represents the point to which you are unable to safely drive, due to the brightness of oncoming lights. Today, we have a situation that requires more light down the road (largely in low beam functions), but we need to come up with a better way to reduce the amount of glare as well.
Light Sources – New light sources have emerged that are contributing to the issues of glare and poor low beam performance. Incandescent and halogen light sources have been available for many years, but the emergence of HID or Xenon Headlamp bulbs has ushered in new areas of concern. HID equipped headlamps can often be identified by the significant improvement light output, but they may give a “cool blue” color temperature in most situations. The beam from an HID headlamp has a great deal of uniform light and its reach down the road is great. Many people who have HID equipped vehicles report that they enjoy the driving experience behind HID equipped headlight systems.
It has become an interesting aftermarket trend to sell “HID blue tinted” halogen bulbs or HID replacement kits, which we strongly recommend that you understand the potential risks before purchasing. If you see an extremely blue headlamp on an older car, with blue headlamps, this is likely the use of an illegal HID kit or a blue-tinted bulbs. This aftermarket product has become quite popular, but causes a tremendous amount of glare. The bulbs are often sold with a label “For off road use only”. A bit of advice: Only use bulbs that are labeled “DOT” and make sure that they are the same bulb type as was recommended by the manufacturer. “DOT” labeled bulbs are available that are both tinted and have additional features designed to improve the performance, and make acceptable choice for most applications. Bulbs with the “For off road use only” designation may even damage your existing headlamp lens and housings.
LED Headlamps are also beginning to emerge. Many of these headlamps have used computer based optics design technology, which is helping to extend the performance of the headlamp, reducing the amount of uncontrolled glare light and increasing the ability to see down the road. LED technology in headlamps has all the great features we have grown to enjoy in exterior lighting like: lower current draw, less heat, longer life, faster start up time, better performance in cold weather and richer colors. We like what we see with the LED headlamps and we believe that the customer experience will even be better forward lighting when the technology matures.
Concept – When headlights were first developed, it was thought that high beams would be the default driving lights, and you’d only temporarily switch to the low beams when approaching someone in traffic or trailing behind another vehicle. That’s not how drivers ended up using them. Most only rarely use their high beams, to avoid blinding oncoming drivers, and it’s become a legal requirement to have them off when another car is approaching. People actually underuse their high beams, which is a strange thing to say, and likely don’t recognize how limited their vision is with low-beam lights. In another recent study by UMTRI where they looked at driving habits and relating to the use of lighting- In the city 93% of the time people are using low beam, 5% of the time High beam headlamps are being used and the other 2% are using no lamps when they need to. Older drivers tend to use high beam headlamps more than younger drivers. Younger drivers tend to drive without headlamps at night at a time when they should be.
Glare – Glare remains a major problem in North America today. Five causes of glare that are apparent are HID light sources (or sources that are likely illegal that look like HID’s), cleanliness of the headlamps, haze from abrasion and chemical attack and improper aiming of the headlamps. Efforts need to be taken to improve the performance of headlamps to reduce the glare.
Future – I am often asked, “what will we be seeing from headlamps in the year 2020?” To answer that question, I would like to share with you some future needs that I see for the application.
1) First, we need a headlight beam that has uniform optical pattern with enough reach to allow for safe driving with low beam headlamps at 55 mph. Advanced engineers are looking at a concept that is beginning to be demonstrated in Europe called Adaptive Main Beam (AMB) headlamps. AMB headlamps will have only one beam much like our high beam pattern that we have now, but that will allow for a very comfortable driving experience at night. You ask, what happens to glare control? The simple answer is that the lamp will be equipped with “beam blockers” which will allow for mechanical or electronic methods to block the beam when shown in the direction of on-coming traffic. This technology also has provisions to prevent blinding the back of a car or truck you are trailing behind. The first demonstrations have shown a great deal of promise and I expect this to emerge as the next renaissance in forward lighting technology.
2) Another need of headlamp technology is for increased light output with lower power draw. The continued path of increasing lumens per watt and the decrease in lumens per dollar shows clearly that LED light sources will become the dominant technology for not only headlamps but for all of the exterior and interior lighting on cars and trucks. LED sources can be integrated into the AMB concept.
I believe that we may see, in 2020, some of the first interactive cars and trucks which will talk to each other and improve the driving experience. The first technical demonstration of this will take place this summer, in Michigan, USA. Interactive cars and trucks with the improved adaptive main beam technology hold promise for a continued improvement in driving safety, making the trip to the store or the basketball game quite a bit safer in the future.
Brad Van Riper
Sr. Vice President of Research & Development , and Chief Technology Officer
Truck-Lite Co., LLC