The term 'Ambulance Feature' refers to a vehicle that is equipped with a SIREN, which is a loud, high-pitched sound used to alert people of an emergency. The SIREN is typically used by ambulances, fire trucks, and police cars to alert people of their presence and to clear the way for them to reach their destination quickly. The SIREN is also used to signal the start and end of a shift or to indicate the arrival of a medical emergency.