In response to “Enlightening technology,” (November issue, page 19):
I have just read your article and have found it very interesting.
One concern that I have for you and the lighting industry is the shear blazing intensity of LED headlights for oncoming drivers. The LED headlights can be overpowering and that in itself could cause accidents. What is being done to address this situation?
LEDs will become the norm as prices shrink with mass production, but they have to be safe.
Your comments, please.
— Bill Neufeld, PhD, councillor, City of Parksville, British Columbia
Public Works' Fleet Management columnist Paul Abelson, responds:
I agree that headlights glaring at you are a safety hazard, masking necessary vision due to contrast. But I am not sure the blame lies with LEDs. In fact, LEDs may represent the solution.
Several years ago, high-intensity discharge (HID) headlamps made their way from Europe to the United States on several luxury cars. They are usually in projector assemblies, with lenses focusing the light where it should be. In Europe, there is usually an adjuster mechanism that can lower the aim of the HIDs when, for example, there is a heavy load in the trunk that raises the front end.
In the United States, we have heavier vehicles, so the problem is not as great. Also, we have different laws concerning lighting, and mechanisms to adjust headlight aim from inside the cab are not allowed.
These statements deal with HIDs, not LEDs. Because LEDs are still developing, multiple diodes are still needed. As manufactured by Truck-Lite, Audi and others with LED headlamps, each diode is focused on a discrete portion of the roadway or the area ahead of the vehicle. With appropriate overlap, the net effect is a brighter, more even light distribution with less energy consumption. If an oncoming driver does notice undue brightness from LEDs, it will be less bright because it will be from only one or two diodes, not the entire light source as with HIDs.
- Paul Abelson (firstname.lastname@example.org) is a former director of the Technology and Maintenance Council (TMC) of the American Trucking Associations, a board member of Truck Writers of North America, and active in the Society of Automotive Engineers.