You are four times more likely to be in a road crash if you use your phone while driving.

And your reaction times if you text and drive are twice as slow as if you drink and drive.

That’s why it’s against the law. Offenders can end up with six penalty points on their licence and a £200 fine. The police are now set to take a tougher line on those using their phone while behind the wheel, and the hope is that the culture shifts so that phone-driving is frowned upon in the same way drink-driving is.

Sometimes a bit of enforcement works better than mere encouragement - stick rather than carrot. It’s been a good idea to reuse plastic bags, fasten your seatbelt and smoke outside for decades, but we didn’t necessarily do it until we were forced to.

However when I heard about the new get-tough approach to phone-driving my first thought was why anyone would want to do both at once anyway.

This mobile phone addiction is something I can’t comprehend.

I have a smartphone. At least it’s quite a smart-looking thing. But I use it mostly for phoning and texting, and when I need to search the internet I’ll use the computer at home or at work. My phone can do all kinds of things I can’t imagine wanting to do.

Maybe I’m a bit of a technophobe - and I’m not proud of it - but I can’t escape the feeling that being an extreme technophile is much worse.

One Saturday afternoon I was in Carlisle library when a group of teenage girls came in, a category of the population that might be most prone to chatter. Yet as soon as they sat down and all turned straight to their phones and didn’t look up from them the whole time I was there. It’s not just TV that kills the art of conversation.

And the evidence is mounting that overuse is harmful.

The journal Clinical Psychological Science published the findings of a study of half a million American teenagers monitored over five years. It showed that kids who used their smartphones for three hours or more a day were one-third more likely to feel hopeless or consider suicide - and that rose to nearly half of those who used them for a daily five hours of more.

If any newly invented gadget was shown to cause youngsters serious psychological damage, we’d probably want a ban on the sale of them to under-18s, and we’d be unlikely to buy them for own kids - even if they protested that all their friends had one.

The only problem is that the smartphone is already here. And what is likely to prevent any restrictions on them is what’s called “status quo bias”.

When something is normal and firmly established, the idea that it is a terrible thing can make it difficult to change. That’s why it took so long for slavery to be abolished, for restriction on tobacco to be introduced and for women to get the vote.

It’s still holding up, in some sectors, their right to equal pay for equal work.

And of course any ban or restriction would provoke predictable complaints about “the nanny state”.

But maybe some people need the nanny state to tell them what to do, and restrict some of their freedoms - like the freedom to drink and then drive home.

Others will complain that a ban would be impossible to enforce. So are the bans on murder and rape. Should they be lifted?

The fact is that a mobile in itself never harmed anyone. Nor does a car or motorbike if used properly. But we can’t trust youngsters to use them properly, so we don’t let them drive. Doesn’t the same apply to smartphones?

One study doesn’t prove beyond any doubt that anything is dangerous. It was a long time before there was any proof that cigarettes caused cancer.

So maybe we should err on the side of caution, and impose some temporary restrictions until all the evidence is in.

If it turns out that they’re not so bad then it won’t have done children too much harm to have been without one for a time. I spent my first 30 years without a mobile and I don’t blame all my problems on that.

It if turns out that they are harmful, then we will have been protecting them. And no-one should object to erring on the side of caution when it comes to protecting the next generation.