The following are the criteria for vehicles that must be registered with the IRP:
Any power unit that is used or intended for use in two or more member jurisdictions and that is used for the transportation of persons for hire or designed, used, or maintained primarily for the transportation of property and:
- has two axles and a gross vehicle weight or registered gross vehicle weight in excess of 26,000 pounds;
- has three or more axles, regardless of weight; or
- is used in combination, when the gross vehicle weight of such combination exceeds 26,000 pounds.