Marks a tunnel where special traffic rules apply.
The sign is normally placed at the tunnel entrance. Prepare for changing light levels and follow any signals or restrictions.
The common pictogram represents a tunnel entrance. Germany’s 327 also requires dipped headlights while travelling through the tunnel.
Official sign in each country; the code is its number in the national rules. Signs that come in two directions show the left and the right version.
Sign images from Wikimedia Commons, used under their licences.
