What should you do?
Prepare for tunnel driving: check your headlights, keep a safe distance and follow lane signals inside the tunnel.
How to recognise it
A white rectangle with black text reading Tollán Chalafort Bhaile Átha Cliath / DUBLIN PORT TUNNEL and 4.5 km.
Common confusion
It is an information sign, not a regulatory one; height limits and tolls are shown on other signs.
Explanation written by the My Driving Test editorial team using the Department of Transport Traffic Signs Manual conventions and the RSA Rules of the Road.
