What lights should be turned on when a car enters a tunnel?
3 Answers
When a car enters a tunnel, the headlights (low beams) should be turned on. At this time, the front low beams and width indicator lights will illuminate, and the rear brake lights will also light up. Since the lighting inside the tunnel is relatively dim, turning on the headlights can alert drivers of vehicles in front and behind to the position of your car, ensuring driving safety. When entering a tunnel, the car should slow down because the bright and glaring light outside the tunnel during the day contrasts sharply with the relatively weak light inside the tunnel. This transition can cause a brief period of eye adjustment for the driver, during which their judgment of road conditions may be impaired. Turning on the car lights not only helps in observing the road conditions but also serves to alert other vehicles.
Turning on the low beams immediately when driving into a tunnel is not just a casual rule. The sudden dimming of light inside the tunnel requires time for the human eyes to adjust. At this moment, the car lights not only help you see the road ahead clearly but, more importantly, make your vehicle noticeable to others. Every time I pass through a tunnel, I first check the position of the light switch, especially in unfamiliar rental cars. Be careful not to use the high beams, as the strong light in an enclosed space can cause diffuse reflection, making all drivers effectively 'blind.' Don’t rush to turn off the lights when exiting the tunnel; it’s safer to wait until you’ve fully adapted to the external light before switching. Some new cars come with automatic headlight functions, but it’s best to manually confirm if they’ve activated promptly when entering a tunnel.
The primary purpose of turning on lights in tunnels is not for illumination but for warning! Those who have experienced it know that the first few seconds upon entering a tunnel can feel like sudden blindness. Last time I drove my friend's older car, I only remembered upon entering the tunnel that it didn't have automatic headlights, and in my panic, I nearly scraped the guardrail. Now I've developed a habit: turning on the low beams 200 meters before the tunnel entrance. I remember once entering a tunnel during heavy rain, the car ahead only had its fog lights on, making its outline barely visible in the gloom—extremely dangerous. Don’t rush to turn off your lights when exiting the tunnel either; on overcast or rainy days when external light is insufficient, keeping them on helps following vehicles spot you earlier. A common mistake new drivers make is using parking lights as headlights—those small bulbs hardly serve as an effective warning.
