When mustn’t you sound your vehicle’s horn?

Explanation: Every effort must be made to prevent excessive noise, especially in built-up areas at night. Don't rev your engine or sound the horn unnecessarily. It's illegal to sound your horn in a built-up area between 11.30 pm and 7.00 am, except when another road user poses a danger.

Category: Safety and your vehicle

References: The Official DVSA Guide to Driving: Section 3, Highway Code: Rule 112