What drivers are debating
A motorist says “99% of drivers” do not know one common UK sign.
They posted on Reddit: “I’m convinced 99% of drivers don’t know what this sign means.”
What the sign looks like
The sign is round with a white background.
It has a thick black diagonal stripe through the middle.
What people guessed online
Some users made jokes in the comments.
One wrote: “National drifting zone.”
Another said: “National speed limit, but what that limit depends on what you’re driving. For example, if you’re driving a BMW, it’s 100mph and excuses you from using indicators.”
One person added: “Oh, that’s the ‘go as fast as you want and overtake on a bend if you feel like it’ sign!”
Another guessed: “It means ‘minimum speed – 80,’” and someone replied: “In my experience, it’s ‘max 40.’”
What it actually means
The sign means the national speed limit applies.
The RAC says: ”A white circular sign with a single black diagonal stripe through it tells you that the national speed limit applies on the upcoming stretch of road.”
“It supersedes any previous speed limit signs you may have had to adhere to, such as passing through temporary roadworks.”
How the national limits work
In built-up areas, the limit is 30mph for all vehicles.
That means street lamps are no more than 200 yards apart.
On a single carriageway, cars can do 60 mph.
Vans and vehicles towing a trailer or caravan can do 50 mph.
On dual carriageways and motorways, cars can do 70 mph.
Vans and vehicles towing a caravan or trailer can do 60 mph.
The RAC warns: “Of course, even when the national speed limit applies, it might not always be safe to drive at that speed, so use your common sense on this,” the RAC warns.