What does it mean if the brake lights on a vehicle are illuminated?

When the brake lights on a vehicle are illuminated, it indicates that the driver is slowing down or coming to a complete stop. This is a crucial signal for other drivers on the road, as illuminated brake lights inform them to be cautious and prepare to adjust their speed or apply their own brakes if necessary.

For instance, when a driver presses the brake pedal, the brake lights activate, providing clear visual communication to those driving behind that the vehicle is reducing speed. This is an essential aspect of road safety, as it helps prevent rear-end collisions by alerting following drivers of the change in speed.

The other options do not accurately depict the function of brake lights. For example, illuminated brake lights do not indicate that the vehicle is speeding up or making a turn, as those actions would typically be communicated through other cues such as turn signals or acceleration. Similarly, while a parked vehicle may have its hazard lights on, its brake lights would not be illuminated if the vehicle is stationary without being engaged in braking. Thus, the correct understanding of illuminated brake lights is vital for safe driving practices.