It has been illegal for years, so why do so many people who would not dream of breaking the law in other ways still routinely use their handheld phones while driving?
It's an offence that carries three penalty points and a £100 fine, or if it goes to court the maximum penalty is a £1,000 fine and a driving ban. Yet take just a short journey on Britain's roads and there's a very good chance you'll see someone using a handheld mobile at the wheel.
According to a recent RAC survey, 31% of motorists admit to using a handheld phone while driving, compared to just 8% in 2014. That's almost a third of drivers. Meanwhile 19% said they had used a phone to send a text message or post on social media websites, while 14% said they had used a phone to take a photo or video while driving.
So why is this law being routinely broken on such a massive and seemingly casual scale? There is probably not one answer, but several.
First, more and more of us, especially younger people, are 'addicted' to mobile phones, spending hours every day using them to talk to and text people, access the internet, update social media websites, play game, use apps and a host of other activities. And like any addiction, it is near impossible to resist, even while doing other important things. Too many people are simply unable to resist reaching for their mobile if it pings, beeps or rings while they are driving.
Second, you'll probably get away with it. It's an offence that's difficult to detect and to enforce. While a network of speed cameras will automatically record you driving too fast, there are no automatic cameras to catch you on the phone. That relies on a police officer spotting you, but according to the RAC there has been a 27% drop in full-time dedicated road policing officers in England and Wales (excluding London) between 2010 and 2015.
While some forces have carried out enforcement campaigns, using cameras to catch drivers on the phone, they are few and far between as the police increasingly prioritise their scant resources. Even in these campaigns, many drivers received only a verbal warning. Do you know of anyone who has been fined or prosecuted for using a mobile at the wheel? When did you last read a report in your local newspaper of someone prosecuted for the offence? It does happen, but it is relatively rare.
Third, too many people don't consider it a "proper offence", after all, it's just being on the phone, something we all do all the time. It's not like excessive speeding, reckless driving or drink-driving, is it? In fact it is exactly like those in that it is something we can choose to do or not. And the effects can be just as devastating.
Countless people have been killed or seriously injured in accidents on British roads in which a driver has been preoccupied with their mobile phone. Latest Department of Transport figures show that in 2014 alone there were 492 accidents in which a driver was impaired or distracted by their mobile phone, 84 of them classed as serious and 21 fatal.
In these cases at least, the proof is there. Phone records reveal exactly what the driver was doing at the time of the accident. The alarming and growing number of such accidents has fed campaigns to clamp down on the offence and vigorously enforce prosecution of it, so that drivers finally begin to take it seriously.
The simple fact is that when behind the wheel a driver's full attention should be focused on the job in hand – driving. Using a handheld mobile phone massively impairs that focus in two ways; by taking at least one hand off the wheel and by occupying the driver's mind.
It is even more baffling when there are alternatives readily available, such as hands-free devices and 'bluetooth' connections, which at least allow a driver to make or take a call without handling their phone. Almost all mobiles also have a voicemail facility whereby a caller can leave a message is their call isn't answered, so why do drivers feel compelled to answer immediately?
Now, in response to growing pressure from campaigners and increasing horror at the carnage caused by some phone-using drivers, the penalties are being beefed up. Under new legislation expected to come into force next year, drivers caught using a handheld mobile at the wheel can expect six penalty points and a £200 fine. Newly qualified drivers could be made to retake their test while more experienced drivers caught for a second time could be taken to court to face a maximum fine of £1,000 and a driving ban of at least six months.
The new penalties will be linked to a high profile awareness campaign, but many campaigners say they don't go far enough, and the problem of effective and determined enforcement will still remain. It could be some time before the message finally hits home.