Understanding advanced safety systems: How BLIS alerts drivers of potential blind spot incidents

Consider this scenario: you are following a vehicle or on the left lane of a highway, approaching another vehicle in the right lane. In such a case, you might see an orange or red light flashing on or near their left mirror. This light serves as a warning that you are approaching them and, crucially, that the vehicle's driver might not be aware of your presence—they haven't noticed you yet.

This is how the BLIS system (Blind Spot Information System) operates. Its purpose is to alert the driver about objects or vehicles in their blind spot—a place the driver might not see even by looking in the mirror or over their shoulder.

The BLIS system surveys a much larger area than just the blind spot. It is designed also to warn the driver about vehicles that may soon enter their blind spot. Typically, this monitored area spans from the central pillar (known as pillar B) to several, or even dozens of meters behind a parallel vehicle. However, it's important to note that the BLIS system doesn't alert drivers about vehicles in the same lane or approaching from behind.

The primary aim of the BLIS system is to prevent collisions, which might transpire if the driver, not noticing a nearby vehicle, decides to change lanes. The system's signal is quite straightforward and unambiguous, but that doesn't guarantee the driver will heed it. Therefore, if you see a flashing light in the mirror of another vehicle, remember that it's a warning for you, too: the driver may not be aware of your proximity.

Pay attention to the turn signals—often situated on vehicle mirrors and potentially similar in appearance to the BLIS system light. This resemblance is especially true with SEAT Leon models. If a driver activates their left turn signal intending to change lanes while you are alongside, they might not have seen you or could be waiting for you to pass or yield.