Speed kills. We know this because it's the mantra constantly being rammed down our throats by everyone from road safety lobbyists past the police to the government itself.

M42 So why, then, has that same government decided to raise the speed limit for drivers using the hard shoulder of the M42 during periods of peak congestion?

Because, despite the fact that motorway hard shoulders are well known to be incredibly dangerous, when the Highways Agency conducted a trial, it discovered that the higher limit (60mph instead of 50mph) had 'no discernible impact on safety'.

What the Government has just discovered is something that responsible, informed and enthusiast drivers have known from day one: speed doesn't kill at all, only its inappropriate use.

The distinction is critical. You can drive past the school gates at 30mph at chucking-out time and, while you may be lethally dangerous, you are not breaking the law and no-one will try to stop you.

But drive a modern car at 85mph down a dry and lightly populated motorway and you'll find yourself ranged against a vast arsenal of ever more sophisticated, expensive and tax-payer funded infrastructures with no discretion, designed to entrap, fine and criminalise you and, if you are an habitual offender, remove you from the road altogether.

What is needed is some simple common sense. Our motorway system is now so covered in electronic display boards that applying and communicating speed limits that vary according to conditions is easy.

When it's foggy, snowing or pouring with rain, who'd argue against a sane, commensurate and temporary reduction in speed limit and its legal enforcement?

Similarly if the sun is out, and the traffic is light, why not let us tootle along at 85mph without fear of recrimination?

It seems like a moderate and measured approach that uses our investment not simply to penalise and tax motorists, but to help us too. Do you think it will ever happen? No, neither do I.