The middle classes would love to be best friends with the police, and are wounded that the small matter of driving offences comes so often between them. It is not a crime, surely, so much as a misunderstanding. Thus, drivers who are sharp as tacks in their professional lives suffer blackouts of memory over who was driving, and shake their heads in wonder over the photographic evidence.

Mobile phones that we never knew we had are clamped to ears in supernatural acts. We blame speed on pressure from cars behind, or saintly trips to the hospital. A woman driver rebuked last week for not strapping children into their rear seats responded that it was all right because they were not actually her children.

I remember ostentatiously slowing on a Somerset dual carriageway to wave on a police car as it raced to catch criminals. The patrol car slowed too, in a lovely, middle-class "after you" moment of choreography. Shrugging with pure affection, I sped on, only to find my new friends, faces now dark, and blue light on, had been trying to pull me in for speeding. Me! Why would they do that?

But if I merely want to be friends with the police, my husband longs to be their alpha student. While I follow the conventional highway code in sight of speed cameras – screeching to a crawl and then roaring off again – my husband is obedient and censorious. When I see points on my licence as a grievous injustice, he asks sanctimoniously what would have happened if small children had wandered across the road ahead.

So you can imagine the perplexity with which he opened a recent letter. It was a terrible mistake. Surely I must have been driving rather than him – and if he had, indeed, been at the wheel, why had I not alerted him to the marked Transit at the road-side? Surely the police had better things to do than prosecute for five miles over the limit....

Happily, his sunny disposition returned: the kind police were prepared to waive his fine and three points in return for his attendance at a speed- awareness course. It was, in the event, if not the happiest day of his life, up there with the best of them. There'd been a slight, last-minute wobble, when a friend reported that the police on his course in another county had been most unpleasant: "You people are as criminal as the yobs that mug old ladies." But Northamptonshire Constabulary had entrusted the task to a cheerful pair of advanced driving instructors – or, in the police language my husband has insisted on using since, ADIs.

The 25 people on his course – "a lovely lot, from all walks of life" – had reverted obediently to the school room, competing to answer questions, joining in discussions, laughing warmly at the instructors' Jeremy Clarkson jokes. The only frustration had been the man who'd hogged the answers, using his unfair advantage as a former driving instructor.

Now a 30mph fob hangs from the car key. My husband changes into third gear in built-up areas, invites me to read the road ahead, and talks excitedly of the next generation of cameras that will judge us by our average speed. He asks why the media choose not to report the 40 per cent reduction in road deaths achieved by "safety camera partnerships", and says he has given excellent feedback in his appraisal form.

Did he have any recommendations for improving the sessions? Only that they should think about expanding them into residential courses.

Sarah Sands is deputy editor of the London Evening Standard