What is SMART's offical DOT status?

Im wondering what the DOT term for the Smart is? I read on the smartusa.com page that in some states they will qualify for HOV (High Occupancy Vehicle) status because the driver takes up half the vehicle. I would love nothing more than to pass all those SUVs in the HOV lane like I do on my bike and have them just stare at me as they eat my dust. Any way, what is the label going to be? eg: The P.T. Cruiser is actually as a Van.