That road sign — a white circle with a single black diagonal stripe — is one that often puzzles even experienced drivers.
It’s officially known as the “National Speed Limit” sign in the United Kingdom and several European countries. When you see it, it means the road’s default national speed limit applies, not a specific posted number.
Here’s what that means in practice:
- 60 mph on single carriageways.
- 70 mph on dual carriageways and motorways.
- For vans or towing vehicles, lower limits apply.
This sign essentially cancels any previous speed restriction and reminds you to drive at the safe maximum allowed for that type of road — but always according to conditions.
In short, it doesn’t mean “no limit,” but rather “return to the standard national limit.” It’s one of the most misunderstood signs on British roads — and yes, most drivers truly don’t know it!
