Hidden dip plate: what it means
The plate warns of a hidden dip ahead. Adjust your driving to the road conditions and the view you have.
What does the hidden dip plate mean?
The plate warns of a hidden dip ahead. Below the other danger triangle, it tells you which hazard to expect. Know your traffic signs explains this use of a supplementary plate.
Adapt your driving to the road conditions. Rule 166 says not to overtake if there is doubt or you cannot see far enough ahead to be sure it is safe.
Quick quiz
What does the sign at the top of this page mean?
- Road humps ahead.
- A hidden dip is ahead.
- A humped bridge ahead.
Show answer
B. A hidden dip is ahead. The plate identifies a hidden dip as the hazard ahead (Know your traffic signs). Source: Know your traffic signs: warning signs, GOV.UK; The Highway Code, rule 146, GOV.UK; The Highway Code, rule 166, GOV.UK; Traffic sign images: image details (spreadsheet), Department for Transport, GOV.UK; Traffic sign images, Department for Transport, GOV.UK
Where will you see it?
Before a hidden dip, below the other danger warning triangle.
What should you do?
Be ready to adjust your speed for the conditions. Do not overtake if your view ahead is too limited to be sure it is safe.
What do people get wrong?
Do not assume a clear view of part of the road makes overtaking safe. Rule 166 requires you to be able to see far enough ahead.
Common questions
What does the Hidden dip road sign mean?
It warns of a hidden dip ahead. The plate specifies the hazard beneath the other danger triangle.
Can I overtake near a hidden dip?
Do not overtake if there is any doubt or you cannot see far enough ahead to be sure it is safe (rule 166).
Compare with
Want to test someone else? Play a road-sign quiz with friends and family.
Sources
Checked on 5 November 2026 against Know your traffic signs (warning signs), The Highway Code rules 146 and 166 and the Department for Transport’s image details list.
- Know your traffic signs: warning signs, GOV.UK
- The Highway Code, rule 146, GOV.UK
- The Highway Code, rule 166, GOV.UK
- Traffic sign images: image details (spreadsheet), Department for Transport, GOV.UK
- Traffic sign images, Department for Transport, GOV.UK
Contains public sector information licensed under the Open Government Licence v3.0. Traffic sign images are Crown copyright, from the Department for Transport. Sources and image credits.