How should you examine the brake lights before a trip?

To effectively examine the brake lights before a trip, it is essential to ensure they illuminate when the brake pedal is pressed. This is a critical safety measure, as functioning brake lights are vital for signaling to other drivers when you are slowing down or stopping. If the brake lights do not activate, it can lead to dangerous situations on the road since drivers behind may not be aware of your intentions, increasing the risk of collisions.

While the other options may seem relevant to the condition of the brake lights, they do not directly address the fundamental necessity of confirming that the lights actually serve their purpose when the brakes are engaged. For example, knowing where the brake lights are located and verifying their color or brightness can be helpful, but those aspects are secondary to the primary function of ensuring that they work when needed. Thus, focusing on the operational aspect of the brake lights provides the most direct assurance of safety before beginning a trip.