Did you know that to make a rude gesture at a speed camera is a criminal offence? This is something I learned this week at a "speed workshop" in Northampton - a three-hour indoctrination session that is offered to speeding motorists as an alternative to getting points on their licence. I had been caught exceeding a 30mph limit by 5mph, which enabled me to qualify for this option. If I had been doing 40mph, instead of 35, I wouldn't have been invited to attend, for people who go as fast as that are given no chance to reform: they are apparently beyond redemption.
There were 14 of us modest offenders seated humbly in a semicircle in a room at the Northampton Indoor Cricket Centre, where on a wall in front of us was a photograph of Earl Spencer opening the facility. Outside, cricketers were practising in the nets.
Two amiable instructors took turns to impress on us the error of our ways. Their first and most challenging objective was to make us feel warmly towards speed cameras. Although the instructors admitted that Northamptonshire is regarded as "the speed camera capital of Great Britain", they said that there were actually only 40 of them in the entire county, and that these were all sited in places where three or more people had been killed or seriously injured in motoring accidents during a three-year period.
"Don't feel aggressive towards speed cameras," they urged us. "Think of them as memorials to people who have lost their lives." This is a whole new way of looking at speed cameras and one that is unlikely to achieve widespread acceptance.
It is, however, easier to regard speed cameras as memorials to the dead than as sensitive humanoids. "Would you gesticulate at a policeman?" asked one of the instructors. "I don't think so. You should know that gesticulating to a camera is also a crime in law."
Remember this if ever you feel tempted to raise two fingers at a speed camera: you could in theory be prosecuted, even if you are observing the speed limit at the time; for speed cameras appear to regard themselves as surrogate policemen.
But despite this intolerable presumption, are they in fact a good thing? I have to admit that, much as I dislike them, I was persuaded that they probably are. Among the battery of statistics to which we were exposed, there was an impressive one that the number of people killed or injured in motor accidents at the sites where speed cameras had been installed had fallen since by 58%.
This, presumably, was 58% of what had always been a tiny number; but if it's true that the cameras have only been installed at what were once accident "black spots", then it means that these "spots" aren't "black" any more. And we were assured that new "black spots" have not sprung up in their place. And one has to admit that, overall, government measures to reduce road deaths and serious injuries have been pretty successful. In the 1960s, about 11,000 people died in motor accidents each year: in 2006, the figure was 3,172. In Northamptonshire alone, 449 people were killed or seriously injured on the roads in 2007, compared with an average of 773 between the years 1994 and 1998 - a fall of 42%. One doesn't, of course, know what part speed cameras have played in this improvement, but they must have made some contribution.
I think so partly because speed cameras are mostly situated in built-up areas where the speed limit is 30mph, and it is in these areas that the greatest carnage takes place: three-quarters of all car crashes happen in them. And of crashes that result in deaths, 46% happen in 30mph zones, as opposed to 50% on open roads and a mere 4% on motorways.
Well, there you are. I am trying to compensate for what the instructors claimed - rightly, I am sure - is a failure of the media to publicise the good news about speed cameras. But there is still the question of whether these "speed workshops" are useful.
People attend them for one reason only: to avoid getting points on their licence. And those who are given this option hardly deserve to be penalised anyway. They are drivers who have inadvertently allowed their speeds to drift up slightly above the limit; not the delinquents who roar through villages with the cheerful abandon of Mr Toad.
While everyone should know the astonishing fact that 80% of pedestrians survive if hit by a car travelling at 30mph, whereas only 20% survive at 35mph, it is the delinquents who most need to have this impressed on them. But there are no arrangements for them to be indoctrinated.
As it is, the workshops are presented not as a form of punishment, but as a voluntarily chosen educational entertainment that you are supposed to enjoy. This works for some people - indeed, one of the participants in my session kept repeating at the end how much she had enjoyed it - but it's not my idea of fun.
We were each made to bond with our neighbours, share our experiences, and address one another by our Christian names, as in some group therapy event. This to me is a punishment almost equivalent to three penalty points. So if I strive harder in future to keep to the speed limit, this may be in part because of what I have learned in my workshop, but more out of fear of the retribution the speed camera may choose to inflict on me next time.
· This week Alexander watched Anthony Minghella's last film, the TV adaptation of Alexander McCall Smith's The No 1 Ladies' Detective Agency - and enjoyed it more than did most of the reviewers: "I want to emigrate to Botswana." He also consumed all coverage of the riveting Sarkozy visit and concluded that the Queen really must get some new speechwriters.
· This article was amended on Monday April 7 2008. We said in the column above that 449 people were killed on the roads of Northamptonshire in 2007, compared with an average of 773 between 1994 and 1998. Those figures included those seriously injured as well as killed. This has been corrected.
