What it means
The P-17b sign warns of a narrowing of the carriageway on the left. The usable part of the road is reduced on that side, so you must anticipate possible movements by other vehicles, adjust your speed, and keep enough lateral clearance. It usually appears before roadworks, narrow passages, bridges, or stretches where part of the left shoulder or lane disappears. When you see it, watch the complementary signs and do not enter the opposite direction unless the road and rules allow it safely. In the test they often ask which side narrows and distinguish it from narrowing on the right or on both sides.
- CategoryWarning signs
- ShapeTriangular, red border
Practise DGT questions featuring this sign
Ten DGT 2026 exam-style questions about signs, with an explanation after each. Free, no signup.
