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.

[RebeccaLynn]

I know many people have encountered the situation where a bulb plus a warning symbol lights up on the dashboard while driving. This actually indicates a fault in the vehicle's lighting system, which could mean an external light is broken or not functioning. Common causes include the bulb itself burning out, the filament breaking due to high temperature or vibration; a blown fuse when the circuit is overloaded for protection; or poor wiring contact and relay failure that can't control the current. I suggest you immediately find a safe place to pull over and check which light—headlight, taillight, or brake light—isn't working. If it's a bulb issue, replacing it yourself is simple and inexpensive; otherwise, take it to a repair shop for troubleshooting. Ignoring it can reduce your visibility during night driving or in bad weather, increasing the risk of a collision, and may also result in a traffic ticket from the police. So don't delay addressing it—safety always comes first. Regular maintenance can prevent these minor issues.

[FernandoDella]

I think this symbol is quite common, just like last week when I was driving and the dashboard displayed that bulb symbol—it directly indicated a lighting issue, possibly a problem with the headlights, turn signals, or taillights. Most of the time, it's due to an aging bulb burning out or a broken filament, which often happens on bumpy roads or after prolonged use. Occasionally, it could be a blown fuse or a loose connector. I fixed it myself by replacing the bulb. My advice is to regularly check the lighting status to prevent issues. Ignoring it can lead to dangerous nighttime driving situations, as others won’t see your brake or turn signals, potentially causing accidents. Handling it isn’t complicated—even beginners can try checking the manual for bulb locations and replacing parts. If unsure, seek professional help—don’t compromise safety over minor issues.

[FaithLynn]

That bulb warning symbol indicates an issue with the vehicle's lighting system, such as a burned-out bulb or malfunction. Common causes include bulb failure, blown fuse, or wiring abnormalities. Immediate attention is recommended to avoid risks. Faulty lights reduce visibility and signaling effectiveness, posing significant hazards especially at night or in rainy/foggy conditions, potentially leading to rear-end collisions or turning accidents. Safety first - pull over promptly to inspect or repair.