'99% of UK drivers' have no idea what common road sign actually means

If you’ve passed your driving test, then you had to pass your Theory, and if you passed your Theory, then you had to know what road signs meant once upon a time.

Yet, it doesn’t take too long sitting behind the wheel to realise that such crucial knowledge eludes plenty of fellow drivers; either that or it’s just ignored altogether.

But with no checks to ensure drivers still actually know their Theory years, or decades, on from being officially allowed to drive on the UK's roads with an instructor beside them, it’s not entirely surprising that some niche signs are forgotten about.

Like, did you know a car with a yellow and black explosion on top of it within a red circle means ‘no vehicles carrying explosives’? Me neither.

Some signs are common enough, however, that you would hope every driver knows them intrinsically, such as speed limits, no entry, and stop signs.

Yet, one aggravated motorist on Reddit is convinced that the vast majority of drivers have no idea what one of the most typical road signs means at all.

The sign that has left one driver venting

Would yo know what this means? (Getty Stock Images)

It couldn’t be simpler. A white circle with a black diagonal stripe cutting through it at a 45-degree angle.

It’s hard to be driving for more than 10 minutes in the UK and not see this sign looming over the road.

But one Reddit user posted the sign in r/drivinguk with the caption: "I'm convinced 99 percent of drivers don't know what this sign means."

Fellow Redditors, all seemingly well aware of what the sign informs drivers, quickly began to joke in the comments.

One quipped: "National speed limit, but what that limit is depends on what you’re driving.

"For example, if you’re driving a BMW it’s 100mph and excuses you from using indicators."

Another user shared the troubling anecdote: "One of the girls at my old hairdressers genuinely thought it meant 'go whatever speed you want.”

As another poster pointed out, going very fast down some roads with that sign could be quite foolish: "There's a road near me with this sign and if you're averaging more than 30 down it you're either a complete plank or suicidal."

The sign, of course, signifies that the National Speed Limit applies, but what exactly does that mean?

What does the National Speed Limit sign mean in the UK?

Though many might know that the sign means National Speed Limit, what the national speed limit actually is could be where confusion arises.

That’s because the national speed limit depends on what road you’re driving on and what vehicle you’re driving in.

The sign riles some motorists up (Getty Stock Images)

In a built-up area with streetlights, the speed limit is 30mph unless otherwise stated, on a single carriageway, it's 60mph for cars, and 50mph for vans and anything bigger, as well as if you're towing something in a car.

Meanwhile, on a dual carriageway and motorway, it's 70mph but 60mph for goods vehicles and cars carrying trailers or caravans.

"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 roadwork,” the RAC explains.

"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.”

So that means, you shouldn’t necessarily drive as fast as the road signs say you’re allowed to if external factors would make doing so dangerous.

Now you definitely know what the sign means, make sure you follow it!