Most Drivers Don’t Know What This Common Road Sign Actually Means

It’s a sign you’ll spot on roads all across the UK, yet one motorist recently suggested that the majority of drivers have no idea what it means. The sign in question is simple: a white circular background with a single black diagonal stripe running across it from corner to corner.

The driver, who posted about it on Reddit, wrote: “I’m convinced 99% of drivers don’t know what this sign means.” And judging by some of the responses, they might not be wrong.

So what exactly does this sign indicate?

According to the RAC, this sign tells drivers that the national speed limit now applies on the stretch of road ahead. In other words, it cancels any lower speed limit that may have been in place previously—whether due to passing through a village, temporary construction zones, or other restricted areas.

However, it’s crucial to understand that the national speed limit doesn’t mean the same speed for every road. It varies depending on the type of vehicle and the road classification:

• 70 mph on motorways and dual carriageways (for cars)

• 60 mph on single carriageway roads (for cars)

• 50–60 mph for vans and larger vehicles, depending on conditions

Even so, just because the national speed limit is permitted, it does not mean it’s always safe to drive at that speed. Weather conditions, visibility, traffic levels, and the condition of the road itself can all affect what is considered a safe driving speed. Drivers should always assess their surroundings and use good judgment.

In essence, this sign is not simply telling you to speed up — it is telling you that you are now responsible for choosing a safe and appropriate speed within the legal limit. This is why it plays such a key role in road safety and traffic flow. Understanding this sign can prevent dangerous driving habits and unnecessary confusion on the road.

So now that you know, you won’t have an excuse the next time you see it.