What are the advantages of LED headlights?

The teeny tiny Light Emitting Diode (LED) is powering the biggest revolution in after-dark driving since cars hit the road more than 120 years ago.

Instead of relying on a pair of over-sized torches pointed into the night, using a single light source and a giant reflector, LEDs provide tailored shafts of individual light which can be combined into the ideal coverage for any road and all conditions.

LEDs first came into cars for interior decoration, daytime running lights and tail lamps - including turn signals which now swoosh across the tail instead of making a basic blink.

Signature LED shapes and bundles have now taken the place of old-school badges for brand identification, also boosting safety by improving visibility in all conditions.

But the real revolution, and the big pay-off, is in headlamps.

Their rapid take-up is a big bonus for drivers, but they also cut power needs (good for EVs), allow slimmer lamps and provide designers with more flexibility and opportunity for styling and brand identification.

“Like an artist’s signature. That’s the freedom LED lights give you,” says Klaus Busse, head of design at FCA in Europe and the man driving Alfa Romeo.

They are also designed to last for the life of the vehicle.

The downside is the cost of crash repairs, as the latest multi-element lamps are costly and complicated to replace.

A full-scale ‘active matrix’ LED package, which uses dozens or hundreds of individual lights sources, is also expensive and can add thousands to the price of anything short of a top-end luxury car which comes with LED lamps as standard. Their replacement cost can be eye-watering.

“This completely changes the playing field,” says Justin Pound, the engineer responsible for headlamps at Holden.

He says the advantages of LEDs start with their size, but go much further.

“The LED itself is a light source. It’s superior to Halogen or Xenon gas, mainly in efficiency. It’s also the way it emits the light, in a cone.

“Because the light is emitted in one direction, you can use it more efficiently. There is also a lot less heat, so you can package the light sources closer together to create a matrix system, linking them to cameras and navigation.”

Laser lights are also coming, mostly for long-distance work, but they are still costly and complicated.

Lighting engineers, including the experts at Hella in Europe, have exploited the LED edge by creating lighting patterns that use complicated shapes for various roads and conditions. They are better for lighting verges, reducing glare, and all-out long-range punch into the dark.

“New generations of headlights are intelligent, high-resolution and multi-functional. The light sources in the headlight can be individually activated, using digitisation for the first time,” says Tomas Plessinger of Hella Australia.

It’s this ‘active matrix’ package that truly turns night into day, as the safety systems in the latest cars can ‘see’ the road ahead through radar and stereo cameras, allowing the LED light to be shaped for any situation.

That can range from low-glare side-to-side coverage at slow speeds to punching a giant long-range hole in the dark on a deserted outback highway.

The matrix systems are programmed for optimum light and maximum safety, which means minimal distraction and glare for other road users. The driver just sets the lights to automatic high beam and the car does the rest.

This can mean a huge wash of coverage on the left-hand edges of the road, shaping the beam around cars heading in the same direction, and reacting quickly to dip the lights when an oncoming vehicle is detected.

From the wheel, the LED advantages include brighter white light, improved visibility in all directions, and no need to worry about dipping the high beam.

“It’s been a great improvement to safety, with visibility on the road, and they look cool with the signature lighting,” says Jeremy Tassone, also at Holden.

He says there are LED set-ups in some versions of the Holden’s Astra, Commodore and Equinox, with much more to come.

“They are a more efficient design and provide better light quality. We have 16 elements on Astra and 32 elements on ZB Commodore.

“On country roads those lights are night and day to anything I have used in the past. It’s almost like they’ve been designed for Australia.

“It’s hard to believe that you are not dazzling people. I’m blown away.”

LEDs are arriving rapidly in all sorts of cars, but Hella says the next step will take things further by directing their light through a liquid crystal display - and linking the lights to a vehicle’s satnav.

“The LED crystals are switchable, which makes it possible to change the polarisation direction of the light. There is a prototype that projects up to 30,000 pixels on the road,” says Plessinger.

“So the headlamp masters driving situations intelligently, continuously and in a targeted fashion.

“This can include pedestrian markings, the illumination of protection zones for cyclists, warnings, navigation symbols or the display of the ideal driving path,” he explained.