What must a driver do if the vehicle's horn cannot be heard from the required distance?

When the vehicle's horn cannot be heard from the required distance, the proper action is to replace the horn. This is essential for ensuring that the vehicle meets safety regulations and is adequately equipped to alert other drivers and pedestrians as needed. A functioning horn is a critical component of vehicle safety, allowing the driver to signal their presence or intent to others on the road.

Simply adjusting the horn placement, cleaning it, or retesting with the same horn does not address the fundamental issue that the horn is not functioning properly or powerfully enough to be heard at the required distance. Replacing the horn ensures that the vehicle adheres to safety inspection standards, thus maintaining road safety for everyone.