To be classified as an ambulance, a vehicle must possess a width less than 96 inches and a loading height of no more than 34 inches. Vehicles unable to meet all government-mandated requirements cannot be classified as ambulances.
Ambulances are classified as one of three types. Type III ambulances are built upon van chassis and have the smallest interior volume and exterior dimensions. Type II ambulances are vans with long wheelbases and are often too cramped for patient transportation. Type I ambulances feature modular chassis with truck-style bodies and separate driving compartments and are often the largest vehicles found in the field.