What happens legally if my vehicle breaks down and causes an accident?

Liability is determined by ordinary principles of negligence, considering what each driver did and whether they acted reasonably in the circumstances. A driver whose vehicle breaks down is generally expected to take reasonable steps to warn other road users and move to a safe position as soon as practicable, for example using hazard lights and, where safe, moving to the shoulder, in line with expectations under the Land Transport Act 1998 and associated road rules about stopping and parking on motorways. The driver approaching from behind also has a duty to maintain a safe following distance and be alert to hazards, and following too closely or failing to react appropriately can make that driver primarily at fault. Fault can be apportioned between drivers depending on the facts. Report the accident to police if required, take photographs of the scene and vehicle positions, gather witness details, and notify your insurer promptly for both vehicle repair and liability purposes.