Minimum speed limit of 40 miles per hour
A blue circle with a white 40. You must drive at least 40 mph unless conditions make it unsafe. Mostly used in long road tunnels (Dartford, the Mersey tunnels, Tyne tunnel) where slow vehicles cause congestion and reduce safety. Look for the 'end of minimum speed limit' sign before braking back to your usual cruising speed.
- Shape
- Circular
- Background
- Blue
- Border
- White
- Text type
- Number (Other)
- Diagram reference
- 672.0
Where you'll see this sign
Long road tunnels and certain motorway-grade approaches with no slow-vehicle lanes.
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