Type I is based upon a heavy truck chassis with a custom rear compartment that is often referred to as a "box."

The driver compartment resembles a pickup truck. The connection between the cab and patient module is a small pass-through that looks like a window. 

Type I ambulances are primarily used for Advanced Life Support(ALS), also referred to as Mobile Intensive Care Unit(MICU) in some jurisdictions, and rescue work.

Type I Silhouette - Alachua County
Type I Silhouette - Glades County
Type I Silhouette - Indian River County Fire Rescue