Overview
- The RAC says drivers often mix up two similar triangular warnings, risking unsafe decisions.
- A red triangle with two vertical lines that stay separate signals a bottleneck where the road narrows on both sides.
- A red triangle with lines that converge marks the end of a dual carriageway as the central reservation disappears and lanes merge into a single carriageway.
- Misreading these signs could be hazardous, so the RAC urges motorists to refresh Highway Code knowledge and watch for lane width changes.
- The Highway Code’s plain red circle with a blank centre means no vehicles may pass, and ignoring it can lead to fines and penalty points.