Automatic High Beams

Automatic High Beams: See and be seen, without a second thought

Nighttime driving accounts for a significant share of road risks, with poor visibility often being the primary cause. To address this issue, manufacturers have developed automatic high beams, an increasingly common Advanced Driver Assistance System (ADAS). Also known as "High Beam Assist" or "Auto High Beam," this intelligent technology automates the switching between low beams (dipped headlights) and high beams (main beams) to constantly ensure the best possible illumination without ever dazzling other drivers.

How do automatic high beams work?

The brain of this system is a digital camera, most often a CMOS camera, housed behind the windshield near the rearview mirror. This strategic position provides it with a clear view of the road. An image processor analyzes the video feed captured by this camera in real time to identify various light sources.

The system is specifically programmed to recognize:

Headlights of oncoming vehicles.

Taillights of vehicles traveling ahead of you.

The characteristic street lighting of urban areas or villages.

In newer systems, reflective light sources such as road signs or the clothing of cyclists and pedestrians.

The logic is simple yet effective: if the system detects none of these light sources, ambient lighting is low, and the vehicle exceeds a certain speed (usually between 40 and 60 km/h / 25 and 37 mph), it automatically engages the high beams. As soon as another vehicle is detected, it instantly switches back to low beams, well before the driver could be dazzled.

What are the practical benefits for the driver?

The contribution of automatic high beams is mainly measured in terms of safety and comfort. Studies have shown that many drivers underuse their high beams out of fear of inconveniencing others or simply by forgetting. The automatic system compensates for this behavior by ensuring maximum utilization of high beams. This extends the field of vision by dozens of meters, providing precious reaction time to anticipate a turn, an obstacle, or an animal on the road.

Furthermore, driving comfort is significantly improved. The driver no longer has to worry about constantly manipulating the lighting stalk on winding country roads. This reduction in mental workload allows them to remain more focused on driving and reduces fatigue during long night journeys.

The Evolution: Towards Adaptive Matrix Headlights

Conventional automatic high beams operate on a binary principle: on or off. However, this technology has paved the way for much more sophisticated systems such as Matrix LED or Multibeam LED headlights. These adaptive lighting systems use the same camera but control dozens of LED segments individually. Instead of completely shutting off the high beams, they are able to create dynamic "shadow zones" around other vehicles while continuing to illuminate the rest of the road with high beams. This is the ultimate stage of intelligent lighting, offering optimal visibility under all circumstances.

Activation and Daily Use

Activating the system is generally very simple. It is done via a button on the headlight stalk (often marked with a headlight symbol and the letter 'A') or through the infotainment system menu. Once activated, a corresponding indicator light appears on the instrument cluster. It is important to note that the driver always retains control: a manual action on the stalk to switch to high beams or flash the headlights will always override the automatic system.