To see or not to see? That is the headlight

I was driving home from work one night about 25 years ago when the guy in an Oldsmobile sedan ahead of me pulled into the parking lane, allowed me to pass and then sped to catch up to me with his high-beams glaring.

After a bit, I pulled over and rolled down my window: “What’s with the brights?”

“It’s because you were shining your brights when you were behind me.”

Actually, I wasn’t, and the next day, I had a mechanic buddy check the headlight alignment. All was fine. (It’s pretty rare for headlights to just go out of alignment without some kind of cause, such as a crash.)

The problem, it turned out, was perception. The guy in the Oldsmobile failed to account for the fact the headlights in my Bronco II were higher than his trunk lid, so they shone right at him. Plus, they were just run-of-the-mill halogens.

Today, we have a similar problem. Driving any number of modern cars, I’ll see oncoming drivers flash their high beams at me as if I was driving with the high beams on.

Modern headlights are becoming extremely effective, but that’s leading to complaints that they are too bright, too dazzling to oncoming drivers. So, I dug into the requirements for headlights in Canada. What a mind-numbing exercise that was.

To get the answer requires first visiting the Transport Canada website to look up Canadian Motor Vehicle Safety Standard 108, which covers lighting for vehicles.

But to get the actual numbers, you first have to get past a cryptic reference to something called ECE 324. Google being my constant companion on this labyrinthine journey, I wound up on the website of, wait for it… the United Nations.

The UN, it seems, has set the standards for headlight illumination adopted by most, if not all, UN member nations.

Once you get here, you have to turn on your geometry and mathematics brain cells. Suffice it to say the regulations are very specific and refer to minimum and maximum illumination at various points in the field of view through the windshield.

Toward the left of the road ahead, the requirements spell out the maximum light permitted to shine. Toward the right, they define minimum illumination.

In other words, they’re designed to force carmakers to produce headlight systems with a specific pattern, more light where you won’t blind someone and less light where you will.

Reduced to the simplest terms, the minimum lighting straight ahead is 25,000 candelas, with the maximums falling off sharply as you move to the left and toward the horizon.

Even just 3.43 degrees to the left and .57 degrees above the horizon, the maximum falls to 350 candelas. (Flip that chart for countries that drive on the wrong side of the road.)

Hayato Mori, senior product manager for Honda Canada, said Honda and Acura vehicles — and by extension, all cars sold in Canada — must conform to these standards.

He said people who mention bright lights as a talking point are generally referring to LED and HID bulbs, both of which are significantly brighter than the halogen headlights most of us grew up using.

“In particular, LED lights are much brighter than HIDs or halogens and reach a lot further out,” he said. “LEDs are also more ‘focused’ light as they use projector lenses, thus they are brighter than your conventional halogens.”

Mercedes-Benz Canada spokeswoman, Nathalie Gravel, said newer headlights are brighter, but added the goal is to balance between better illumination for drivers and not blinding oncoming drivers. She pointed to such technology as automatic switching between high and low beam when an oncoming car is detected.

She also said regulations in North America are behind current advances in technology.

“For instance, we cannot offer the Intelligent Light System that automatically varies the beam pattern depending on road conditions. It is also why we can’t offerAdaptive Brake Lights which can potentially allow following traffic to react more quickly when there is the risk of an accident,” she said.

Moreover, since the LEDs and HIDs produce light that is much closer to white light — given that white light is a composite of all colours in the visible spectrum — the newer lighting systems will appear brighter than the yellowy halogens of old.

Halogens will also dim more rapidly over time than either LEDs or HIDs, so if a car with HIDs is travelling in convoy with cars with well-aged halogens, that car will stand out.

Are new headlights too bright? Not according to the regulations, and because the light from both HIDs and LEDs is very directional, it’s pretty easy to avoid being blinded.

Danny Kok, principal instructor for all Mercedes-Benz advanced-driving programs, said if you are being approached by lights you feel are too bright, look at the right shoulder of the road, and possibly reduce speed slightly and slowly.

“Although we always suggest to look as far down the road as possible if you do that with bright lights coming at you, you will be blinded and not be able to see the road,” he said.

Technology is making it easier for drivers to see, which is a good thing, but it’s also something oncoming drivers will have to adjust to.

So here’s a million-dollar idea that I just don’t have the resources to bring to fruition: Using a layer of LCD film between the glass laminations of the windscreen, and a computer to calculate the position of the driver’s head and oncoming bright lights, it would not be impossible to darken the windscreen at the point where the light intersects on its way to the driver’s eyes.

I’ll let you know where to send the royalty cheques.

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