Maximum speed limit sign

What it means

This is a mandatory speed limit. The number is the maximum speed, in mph, at which traffic may travel, if it is safe to do so.

The same design is used for every limit, such as 20, 30, 40, 50 or 60 mph. The official example shows 30 mph.

A larger sign marks the start of a limit and smaller repeater signs act as reminders. Roads with street lighting don't get 30 mph repeaters, because street lighting already means a 30 mph limit unless signs show otherwise. In Wales, that default is 20 mph.

The red ring is what makes it a legal limit. A speed on a rectangular plate is advice, and so is a speed on a motorway signal that isn't in a red circle.

What the symbol shows

The number inside the red ring is the maximum speed in miles per hour. The red ring is what makes it a legal limit: a speed on a rectangular plate is only advice.

Memory tip: Red ring sets the ceiling; a blue circle sets the floor.

Where you'll see it

At the start of a speed limit, often at the boundary of a town or village, with smaller repeaters along the road.

Rules to know

• The number is the maximum speed, in miles per hour, at which traffic may travel, if it is safe to do so.

  Know Your Traffic Signs, p. 21

• In areas of street lighting (other than motorways), a 30 mph limit applies unless signs show otherwise. In Wales, this limit is 20 mph.

  Know Your Traffic Signs, p. 21

• You must not exceed the maximum speed limits for the road and for your vehicle.

  The Highway Code, Rule 124

What happens if you ignore it

• The minimum penalty for speeding is a £100 fine and 3 penalty points on your licence.

  Speeding penalties, Speeding penalties

• If the case goes to court, the fine is usually a percentage of your weekly income, up to £1,000 (£2,500 on a motorway).

  Speeding penalties, Speeding penalties

• Exceeding the statutory speed limit on a public road carries 3 to 6 penalty points (endorsement code SP30).

  Penalty points (endorsements): endorsement codes and penalty points, Endorsement code SP30

General information, not legal advice. Enforcement can differ between areas.

Spot the difference

Maximum speed limit vs Minimum speed

The key difference: A red ring sets the most you may do. A blue circle sets the least you must do, unless that's impracticable or unsafe.

Differences between the Maximum speed limit and Minimum speed signs

	Maximum speed limit	Minimum speed
Looks like	Black number in a red ring	White number on a blue circle
Means	Maximum speed	Minimum speed

Know Your Traffic Signs, Speed limit signs, pp. 21 and 23

Common mistakes

• Mistake: Driving at the limit whatever the conditions.

  Instead: The limit is a maximum, not a target. Slow down when the road, weather or traffic call for it.

• Mistake: Treating a speed on a yellow or white rectangle as the legal limit.

  Instead: Only a number in a red ring is a mandatory limit. Rectangular 'Max speed' signs show an advised speed.

Test yourself

Recalling the answer helps it stick. Pick an answer to see how you did.

Question 1 of 2

What does this sign mean?

• AYou must keep to the left of the sign.
• BYou must not go slower than the speed shown, unless it's impracticable or unsafe.
• CYou must not go faster than the number shown, in mph.
• DShows the maximum speed advised, in mph, through road works.

Full road sign quizzes are coming soon. See what's planned