Use of the horn while stationary, at night in a residential area, or in an aggressive manner is against the Highway Code.
It says motorists should beep their horns only “while your vehicle is moving and you need to warn other road users of your presence”.
The horn should not be used while stationary on the road or when driving in a built-up area between 11.30pm and 7am “except when another vehicle poses a danger”.
Although breaching the code is not a criminal offence, many of its guidelines refer to legal requirements, and the instructions on using the horn is one of them.
Improper use of the horn is contrary to regulation 99 (1) of the Road Vehicles (Construction and Use) Regulations 1986, section 42 of the Road Traffic Act 1988 and Schedule 2 to the Road Traffic Offenders Act 1988′.
For what he judges to be improper use, a police officer can issue a motorist caught breaking the law with a £30 fixed penalty notice.
Drivers can challenge the decision at court, but if magistrates agree with the police they can increase the fine to up to £1,000.