§47-1-173.1.

§47-1-173.1.
   
   Tank Vehicle.
   
   Any commercial motor vehicle designed to transport any liquid or
   gaseous materials within a tank that is either permanently or
   temporarily attached to the vehicle or the chassis. Such vehicles
   include but are not limited to cargo tanks and portable tanks as
   defined by 49 C.F.R., Part 171. Provided however, the term "tank
   vehicle" shall not include a portable tank having a rated capacity of
   under one thousand (1,000) gallons.