According to a recent survey by YouGov, almost one in ten drivers admit to having crashed into a parked car and driven away without leaving their details. About 70 per cent of drivers have had their cars damaged in this way.

Drivers manoeuvring to park are the most common culprits in bump-and-run incidents. Such incidents are twice as likely to happen in a supermarket car park as in a residential road. So, there’s a steering-wheel delinquent in every checkout queue.

If you hit another vehicle and zoom off, you’ve committed a crime. And that applies not just to people driving cars or lorries but to any mechanically-propelled vehicle.

Section 170 of the Road Traffic Act 1988 (which has been amended in various ways since it was passed) says that any driver who causes damage to another vehicle or to property, or who injures another person, must stop. They must give their name and address (and the name and address of the owner of the vehicle if it belongs to someone else), along with the vehicle’s licence number. The driver need only show their insurance documents if someone has been injured.

The obligation to stop if property is damaged includes things such as walls and fences. It also includes various animals: horses, sheep and dogs — but not cats. The omission of cats from the list isn’t a licence for them to be hit without a care: leaving a cat hit and injured could amount to causing it unnecessary suffering, which is itself an offence under another law.

Even if a car is hit in a car park or in a quiet road while the owner is elsewhere, the guilty driver’s details must still be left by, say, leaving a note under the windscreen wiper. The 1988 Act says that if notification isn’t given at the time of the accident, the culprit must do so in person at a police station or to a police constable “as soon as is reasonably practicable” and, in any case, not more than 24 hours later. Anyone who fails to stop and give their details and then fails to report the matter to the police is committing two offences; each one carries a maximum six-month custodial sentence, a fine, up to 10 penalty points, and a possible driving ban.

There are now 33 million vehicles on the road in the UK. So there have been a fair number of disputes about exactly how this area of law should work in practice. Some things that might seem obvious none the less need to be determined in the courts – such as what is meant by the words “the driver” in the legislation.

In 1996, Jonathan Cawthorn was driving his Peugeot near Blaydon, Tyne and Wear. He parked his car and got out to post a letter but the car rolled away and crashed into a wall. Mr Cawthorn then secured the car and went off. He was convicted of failing to stop and of failing to report the accident. He appealed, arguing that the law required “the driver” to report accidents but as he was out of the car when it crashed, he wasn’t the driver.

His conviction, though, was upheld by the High Court. Mr Justice Forbes said the offence of failing to report an accident is “not a driving offence as such” — in other words, it is not to do with how you drive but what you do after you crash. The “driver” in this context, he ruled, was Mr Cawthorn; it didn’t matter that he wasn’t actually driving at the moment of the collision.

Under earlier law, it was sometimes possible for a defendant to escape conviction by convincing a court that he had no idea he had hit something. In July 1977, at Bow Street magistrates’ court, Lord Harewood was prosecuted for failing to stop and for failing to report an accident. His car hit another car while he was reversing outside the Coliseum theatre in London. But Lord Harewood managed to persuade the court that he didn’t realise he had backed his Jaguar into an MG because he was listening to a Mozart wind serenade on his car radio.

When he hit the MG a car alarm went off but Lord Harewood said he had thought that sound was a sustained clarinet note. The Bench was wooed by the serenade argument and acquitted the noble lord.

The law is no longer that lenient and bump-and-run offenders, if caught, won’t be able to plead Mozart as a defence. Not even The Magic Flute will do the trick.

Professor Gary Slapper is Director of the Centre for Law at the Open University

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