S omewhere, lost and alone on a West Country motorway is a man driving a gritting lorry. He set out when the roads were slick with snow, the sky lead grey and the television news smitten with snow blindness; no other news seemed to matter.

The snow disappeared but that poor man is still out there, looking for a snow-covered motorway on to which he can jettison his salt-laden grit.

You may by now be thinking that I've finally taken leave of my senses – not so! You see the above declaration is my analysis as the reason why those big hanging signs at the side of the M4 still blatantly declare that "salt spreading" is in operation.

Of course, there are other reasons why the signs say salt is being spread, even though the roads are crystal clear. Number one could be that there's a big snow storm or series of blizzards due that the powers that be don't want you to know about. Perhaps it's going to be the biggest blizzard ever and the Highways Agency is determined to cope – even if half of us get buried alive because we don't know it's coming.

On the other hand, the reason the sign is still blinking away may be due to something far simpler – the man who switched it on in the first place went on holiday when the snow had only just started and hasn't come back yet.

This, of course, would present no problems, as long as more than one person had been trained to turn the switch that operates the sign on and off. If only that absentee has been trained in the task, then we'll have to wait until he gets back before we see a more suitable message on the board such as "queue on slip road" or "think bike" or even "distractions cause accidents".

Actually, I made that last one up myself, though Highways really should take it on board. I crane my neck and squint to read their silly signs – and I have to say some of them are silly.

"Tiredness kills"; "Eleven miles to junction 17 – eleven minutes": so you put your foot down in order to make junction 17 in eleven minutes. Isn't that what it says?

Yes, of course it does, but it is encouraging you to do the 11 miles in 11 minutes – one minute per hour equals 60mph – well, sometimes it does.

Getting stuck behind a low loader at 45mph means you have to make up the time in order to make the junction in the time envisaged on the sign.

Hands up all those who think this is getting complicated. OK. Everyone over 50 step forward.

Besides delinquent signs, there are a lot of roadworks on the motorways at present. Lots of red and white cones – my, my, do I wish I'd invented them! Lots of men working, lanes narrowed, but the traffic moving forward.

But that's on a motorway: not so on minor roads.

In South Gloucestershire, not far from the village of Cromhall, new kerbstones are being laid and there are traffic lights in place.

Can somebody please tell me why the queue of traffic from each end has to be escorted through this paltry length? If the men working there are in danger, then those working on the motorway are dancing with death!

But that's what it says: "Caution. Men working".

Actually, when I went through there was only one man working over by the hedge, well away from the traffic. Two more were standing with their hands in their pockets by the traffic lights and the man in the escort vehicle was just driving up and down. Nice work if you can get it.

The snow and ice came and went, leaving behind potholes the size of moon craters. So if you do see a distressed gritter driver unsure what to do with his load, get him to fill them in, then send him home. Tell him it's all over – we hope.