The History Of Adaptive Headlights

Not all headlights are made equal - but adaptive headlights have come a long way.

What makes for good car headlights? It isn't merely how bright the lights are, or how far they're projected and how wide the spread is. They have to be both bright as well as able to avoid blinding other road users, which is why the more complex systems will even have automatic levelling that ties in with suspension movement.

But one particularly tricky situation is what happens when you come to a tighter corner. Regardless of how wide the spread of your beam is, it can be hard to see what's around a corner because of the way your beams travel in the direction the car is pointed - not where your wheels are pointed. Depending on how sharp the corner is, you may find that the direction you're heading in is simply not well lit enough.

There have been a couple of novel ways to get around this. One of the earliest examples of this was back in 1967, with the Citroen DS and SM. The headlights would swivel with steering input, even up to 80 degrees from straight - an incredibly effective way of lighting the bends and hairpins ahead. It was a fairly crude yet effective solution, with rods and wires connecting the steering system to the headlights.

This kind of system is similar to what you find on modern cars, but there were many interim solutions as well. Even our humble Protons had something known as a cornering side lamp, which would come on when you activated a turn signal or turned the steering wheel in their direction. This is also a solution that persists to this day on many cars across different price brackets.

We mention this, because it is this system of additional directional lamps that is currently the solution found with BMW's Laser Light headlights - as they aren't designed to swivel with steering input. For a bit of background, laser light headlights bounce a laser off a reflective element that adjusts and lights the road ahead - but it does so in a manner that avoids blinding oncoming cars and maximizes visible area.

The problem is such a precisely designed system cannot simply swivel around to view the road around a bend. Hence, the additional cornering lamps are used in its place - although less complex lighting systems are still able to swivel the main and high beams around bends.

So there you have it. Of course the best solution would have lights on at all times, spread in all directions like the sighting lights in rally cars - but this would also blind and upset nearly everyone else on the road so you can see why that just isn't an option.