which lights should you use when you're driving in a tunnel

Use your dipped headlights when you’re driving in a tunnel.

Quick Scoop

• Turn on dipped (low‑beam) headlights before you enter the tunnel so you can see and be seen clearly.

• Do not use sidelights only, and avoid full beam because it can dazzle other drivers in the confined space.

• Take off sunglasses and slow slightly as the light level changes; many tunnels legally require headlights to be on.

What the rules and tests say

• UK-style theory-test guidance gives the specific answer: use dipped headlights in a tunnel, and switch them on before you enter.

• Safety advice sites also stress: remove sunglasses, keep a safe gap, and be ready for changing light and traffic conditions.

Simple example

Imagine leaving bright sunshine and heading into a long tunnel.
If you stay on sidelights, drivers behind may barely see you; if you use full beam, you can blind oncoming traffic.
Dipped headlights give a balanced light level so everyone can see without glare, which is why they’re the recommended and often legally required choice.

“Before entering a tunnel, you should switch on your dipped headlights as this will allow you to see and be seen. In many tunnels, it’s a legal requirement.”

Information gathered from public forums or data available on the internet and portrayed here.