What must you observe when you enter a tunnel?

When entering a tunnel in Germany, you must switch on your dipped headlights even during the day, regardless of how well-lit the tunnel appears. This improves visibility for you and other drivers. Also, you should take off your sunglasses because tunnels are often darker than the outside environment, and sunglasses can reduce your ability to see clearly inside the tunnel. Using fog lamps is not required unless visibility is poor due to fog or other weather conditions; simply entering the tunnel does not justify turning them on. Following these rules helps ensure safety in tunnels.