"Driver" means any individual who, in the course of employment, drives a motor vehicle at any time;
"Gross vehicle weight" includes the truck chassis with lubricants, water and full tank or tanks of fuel, plus the weight of the cab or driver's compartment, body, and special chassis and body equipment, and payload;
"Motor vehicle" means any automobile, truck, truck-tractor, trailer, semi-trailer, motorcycle, or similar vehicle propelled or drawn by mechanical power and designed for use as a means of transportation but shall not include any vehicle operated exclusively on rails;
"Outside helper" means any individual, other than a driver, whose work includes riding on a motor vehicle outside the cab for the purpose of assisting in transporting or delivering goods.
This subsection shall not apply to any occupation of motor vehicle driver which involves towing of vehicles.
Haw. Code R. § 12-25-42