Which of the following is a time when the headlight is not allowed to be dimmed?

• A. In tunnel sections
• B. Approaching and passing over public crossing at grade when being approached by an opposing train or engine
• C. In daylight hours
• D. In yard tracks only

Answer: (B)

Headlights are kept bright to maximize visibility for you and to make your train clearly seen by others. The moment you must not dim is when you’re approaching and passing over a public crossing at grade while an opposing train or engine is approaching you. In that situation, keeping the headlight at full brightness helps the other crew and the crossing warning devices see you clearly and ensures you can spot the oncoming train and the crossing signals. Dim routing in this scenario could hide your presence and raise the risk of a collision or missing the crossing safeguards. Other times, such as in tunnels, daylight, or yard areas, there are different rules about dimming that depend on safety and lighting conditions, but the critical safety rule here is not to dim when another train is approaching from the opposite direction at a grade crossing.