20 mph speed limit sign: what it means
The 20 mph sign means the maximum speed on that road is 20 miles per hour. It is the fastest you may drive there, and only when it is safe.
What does the 20 mph speed limit sign mean?
A red ring around a number gives the maximum speed in miles per hour, and you must not go faster (Rule 124). Know your traffic signs adds that it is the most you may travel “if it is safe to do so”.
The large sign marks the start of the limit. Smaller repeater signs along the road remind you that it still applies.
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.
- Maximum speed 30 mph.
Show answer
B. Maximum speed 20 mph. A red ring around a number is a maximum speed limit (Know your traffic signs). Source: The Highway Code, rule 124, GOV.UK; The Highway Code, rule 152, GOV.UK; The Highway Code, rule 207, GOV.UK; Know your traffic signs: speed limit signs, GOV.UK; Know your traffic signs: warning signs, GOV.UK; Traffic sign images, Department for Transport, GOV.UK
Where will you see it?
On residential streets, near schools and shops, and in many town centres. Rule 152 says a 20 mph limit may be in force in residential areas, where you should look out for children running out between parked cars, doors opening and cyclists. In Wales, 20 mph is the general limit on roads with street lights unless signs show otherwise (Rule 124).
What should you do?
Keep to 20 mph or less until a sign shows a different limit. Check your speedometer: 20 mph feels slow, and it is easy to creep up to 25 or 30 on an open street. rule 207 explains why it matters: at 20 mph there is about a 1 in 20 chance of a pedestrian being killed in a collision, at 40 mph your car will probably kill them.
What do people get wrong?
Thinking a 20 mph sign only applies at school times. A fixed 20 mph sign in a red ring applies at all times. The part-time 20 mph near some schools is a different, advisory sign with flashing lights, shown in the warning signs chapter of Know your traffic signs.
Common questions
Is 20 mph the default limit in Wales?
Yes. In Wales the general limit on roads with street lights (other than motorways) is 20 mph unless signs show otherwise. In England and Scotland it is 30 mph.
Is a 20 mph limit the same as a 20 mph zone?
Not quite. Both limit you to 20 mph, but a 20 mph zone sign also warns that the area has traffic-calming features such as road humps, which may not be signed one by one.
Compare with
20 mph zone signA 20 mph limit with traffic calming ahead.
30 mph speed limit signMaximum speed 30 mph.
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 (speed limit signs) and The Highway Code rules 124, 152 and 207.
- The Highway Code, rule 124, GOV.UK
- The Highway Code, rule 152, GOV.UK
- The Highway Code, rule 207, GOV.UK
- Know your traffic signs: speed limit signs, GOV.UK
- Know your traffic signs: warning signs, 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.