20 mph zone sign: what it means
The 20 mph zone sign marks the entrance to an area where the speed limit is 20 mph and where you may meet traffic-calming features, such as road humps and narrowings.
What does the 20 mph zone sign mean?
Know your traffic signs says the zone entry sign shows a 20 mph speed limit and also warns that you are entering an area with traffic-calming features. These features may not be signed one by one inside the zone.
The 20 mph limit lasts until you pass the end-of-zone sign, which shows the speed limit that starts there, such as 30 mph.
Quick quiz
What does the sign at the top of this page mean?
- A 20 mph limit with traffic calming ahead.
- Maximum speed 20 mph.
- Road humps ahead.
Show answer
A. A 20 mph limit with traffic calming ahead. It marks the entrance to a 20 mph zone, where traffic-calming features may not be signed one by one (Know your traffic signs). Source: Know your traffic signs: traffic calming, GOV.UK; Know your traffic signs: speed limit signs, GOV.UK; The Highway Code, rule 153, GOV.UK; The Highway Code, rule 152, GOV.UK; Traffic sign images, Department for Transport, GOV.UK
Where will you see it?
At the entrance to housing estates, residential streets and areas around schools. Inside you can expect road humps, chicanes and road narrowings. rule 153 says to reduce your speed for these features and keep it low along the whole stretch.
What should you do?
Keep to 20 mph or less for the whole zone, not just at the humps. Do not overtake other moving road users in a traffic-calmed area, and give way to oncoming traffic where signs tell you to (The Highway Code, rule 153).
What do people get wrong?
Slowing down for each hump and speeding up between them. The limit is 20 mph everywhere in the zone, until the end-of-zone sign.
Common questions
Where does a 20 mph zone end?
At the end-of-zone sign, which also shows the next speed limit, such as 30 mph.
Will every road hump in the zone have its own sign?
No. Know your traffic signs says the features inside a 20 mph zone may not be individually signed.
Compare with
Want to test someone else? Play a road-sign quiz with friends and family.
Sources
Checked on 3 November 2026 against Know your traffic signs (traffic calming; speed limit signs) and The Highway Code rules 152 and 153.
- Know your traffic signs: traffic calming, GOV.UK
- Know your traffic signs: speed limit signs, GOV.UK
- The Highway Code, rule 153, GOV.UK
- The Highway Code, rule 152, 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.