There is a frightening level of ignorance about mobile phone law, with 21% not realising it is illegal to check Facebook and Twitter while driving, according to the RAC.

Its research also found that more than one-in-ten (12%) do not know that texting and driving is illegal.

Ignorance about texting at the wheel of a stationary car with the engine on is higher still with 61% not realising it is against the law.

The law regarding in-car mobile phone use says it is an offence for anyone to use any type of hand-held communications device when driving.

The definition of driving includes whenever the engine is switched on, even if the vehicle is stationary.

 It is therefore an offence to use a hand-held mobile phone or smartphone when the vehicle is stopped at traffic lights, is stationary in a traffic jam or is parked with the engine running.

But the survey found that nearly half (47%) of motorists think it acceptable to use a mobile phone while sat in traffic lights or stuck in congestion.

Around a quarter (26%) think it safe to text and look at social media sites when stationary with the engine running.

David Bizley, technical director at RAC, said: “While the law is clear it seems that motorists regard using a mobile phone while stationary at traffic lights or when stationary in congestion as more socially acceptable and less dangerous than using their hand-held phones while on the move.

“They forget, for example, that when concentrating on their phone, a cyclist may pull up beside or just ahead of them and they may pull away, totally unaware of the cyclist’s presence.”

Seeing other motorists flouting the law

There is a big difference in what motorists see being done by others and what they are prepared to admit to doing themselves.

More than half of motorists (53%) surveyed report regularly seeing other people texting in stationary traffic during half or some of their journeys, while 29% claim to see this during most journeys.

Three-quarters (75%) of motorists report regularly observing other people talking on a hand-held phone while driving, with 44% saying they see this happening during most of their car journeys.

Motorists with less than 10 years’ experience are more likely to admit to talking on a hand-held mobile phone illegally (16%) compared to just 4% of those who have been driving for more than 25 years.

And, when it comes to drivers owning up to texting in stationary vehicles on the road, only 7% of motorists say they do, though this figure almost doubles to 15% for 17 to 24-year-olds.

Belief they won’t get caught

There seems to be a perception among many motorists – rightly or wrongly – that they won’t get caught if they use their mobile phones while driving.

More than half (51%) believe it is unlikely that they will be caught sending texts while their car is stationary.

And, four in 10 (42%) of motorists also think it is unlikely they will be caught texting while driving, with 16% believing it is ‘extremely unlikely’ they will get caught.

Bizley said: “There is a huge discrepancy between what motorists report they are seeing when they drive and what they admit to doing themselves.

“This suggests some drivers are being economical with the truth and they simply do not consider themselves as being ‘one of them’.

“Yet of those motorists who admit to having used a hand-held phone or having texted or checked out social media while driving, 90% know they are breaking the law.

Driver distraction

“The distraction caused by hand-held mobile phones ranks alongside the cost of fuel and the state of the roads as a major worry for motorists," Bizley said.

"More than a third (34%) worry about other drivers being distracted by talking on mobile phones while at the wheel.

"And, it is the older generation who are most concerned about this with half (49%) of motorists aged 65 or over voicing discontent – a 9% increase compared to 12 months ago.”

More than a quarter of motorists (27%) admit to feeling side-tracked when they hear a mobile phone ring-tone and this rises to 40% of younger motorists aged 17 to 24.

While motorists don’t believe that technology is as big a distraction as other passengers, or changing the CD when driving, 16% of them indicate that looking at their smartphone to read something can be an irresistible distraction; and this rises to 25% among company car drivers.

Just 11% of motorists admit that texting is a key distraction while driving. However, this increases to 16% of 17 to 24-year-olds and one in five (20%) of motorists living in London.

 Bizley added: “British motorists regard themselves as law-abiding and out of 35.8 million driving licence holders in the UK, around three million (less than one in 10) drivers have points on their licence.

"However, more than one million drivers have been convicted of using a hand-held mobile phone while driving since 2003, when it was made explicitly illegal.

"This prompts the question as to whether motorists are deliberately flouting the law or whether they are just unaware of exactly what is, and what isn’t legal."