Emergency vehicles must be equipped with a sound that is audible under normal conditions at a minimum distance of how many feet?

Emergency vehicles are required to be equipped with a sound, commonly known as a siren or horn, that is audible under normal conditions from a minimum distance of 500 feet. This requirement is crucial for ensuring that other road users can hear the approaching emergency vehicle and react appropriately to yield the right of way, thereby facilitating emergency response and ensuring public safety. The distance of 500 feet provides a significant buffer, giving enough time for drivers and pedestrians to be alerted and take necessary actions to clear the way. This standard not only helps in preventing accidents but also enhances the efficiency of emergency responses during critical situations.