Minimum speed limit of 30 miles per hour

Speed limit signs

Minimum speed limit of 30 miles per hour

A blue circle with a white 30 — the inverse of the red-circle prohibition. You must drive at LEAST 30 mph here unless conditions (weather, traffic, road blockage) make it unsafe. Used in tunnels and on certain motorway slip roads where slow traffic is a hazard. Drive too slowly and you become an obstacle to traffic behind you.

Shape
Circular
Background
Blue
Border
White
Text type
Number (Other)
Diagram reference
672.0

Test yourself on UK road signs

How well do you really know your road signs? New Driver Hub's free mock theory test pulls from official-style DVSA questions and tells you which signs you keep getting wrong.

Start a free mock →

Related speed limit signs

See all speed limit signs →