Research revealed three quarters of drivers no longer know the meaning of all the road signs featured in the Highway Code.
The most common signs drivers do not really understand are those involving bridges, loading zones and no motor vehicles.
Also confusing to Brit motorists are what the shape and colour of the signs actually mean.
Alarmingly, only 14 per cent of those under 24 are fully confident in naming road signs, despite having taken their test in recent years.
Three quarters of the younger age group were unable to correctly name the sign which warns a hump bridge lies ahead.
And two out of five didn’t know the sign for risk of grounding, with more than half thinking it meant ‘bumpy road’.
Unsurprisingly, three out of five people aged 55, who have spent years behind the wheel, said they felt confident naming all road signs.
Most adults were not even aware there are three different types of road signs, giving orders, warning people and informing, all signified by different shapes.
Over 60 per cent of drivers didn’t know the meanings behind a road sign in blue circle, which is a sign giving an order.
David Carter, spokesman for Accident Advice Helpline, which commissioned the research, said: “Road signs are segregated into three shapes; circles to give order, triangles warn and rectangles inform people.
”It was surprising to see how many drivers were unaware of the significance of the shape of a sign let alone its meaning.
“It’s worrying how many people don’t know basic road signs when driving their vehicle.
”Understanding road signs are vital to road safety and not knowing their meaning can result in accidents due to ignorance.”
Nearly two thirds of drivers didn’t know the meaning behind a blue circle sign, with 16 per cent of those under 24 believing it meant a restriction zone.
A staggering 43 per cent misunderstood the sign for no motor vehicles, thinking it means cars and motorbikes only.
And one quarter admit there are some signs they will actively ignore with more than one in ten disregarding speed limit signs.
A further eight per cent confess to ignoring loading zones and six per cent disregarding parking restrictions.
It also emerged the lack of knowledge motorists have about road signs can spell danger, with one in five drivers being involved in a near-miss.
And one in twenty being involved in a road accident because either they or another driver didn’t understand a road sign.
Men show more confidence than women with 58 per cent of men claiming to be fully confident compared to 48 per cent of women.
Residents from the east Midlands claim to recall the most, with one third claiming they could remember everything from their driving test compared to less than one fifth from Wales.