Q601: Is it illegal to drive a car with a broken speedometer?
Any speedometer that is fitted to a vehicle must be kept in good working order whilst the vehicle is being used on a road. The penalty for failing to have a speedometer in good working order is a fine.
However, if the speedometer develops a fault whilst being used or a defect has been discovered then all steps must be taken to rectify the fault with reasonable expedition. This exception only applies when the defect develops and must be repaired before the next journey.