What does the traffic sign with a question mark and a light bulb mean?

[DelMariana]

The traffic sign with a question mark and a light bulb is a reminder for drivers not to forget to turn off their headlights after exiting a tunnel. This sign is usually placed at the exit of tunnels on highways. Inside tunnels, the lighting is dim, prompting drivers to turn on their headlights for better visibility. However, many drivers forget to turn them off after exiting the tunnel. This behavior is not only harmful to the vehicle but also poses a safety hazard to other drivers. Hence, such signs are installed to remind drivers to switch off their headlights after leaving the tunnel. When driving on highways, always remember two key points: first, turn off your high beams after exiting the tunnel if you had them on inside, and second, make adjustments to your side and rearview mirrors to minimize the impact of other drivers' high beams on your visibility.