growth vehicle mass of a Goods carrying commercial vehicle is the sum of its tare mass and the mass of goods the vehicle can safely carry in accordance with its design specifications tare mass is determined by weighing the unladen vehicle on suitable vehicle scales it is a legal requirement that this value together with gross vehicle mass be registered on the vehicle chassis frame on an articulated vehicle the combined mass of the prime mover and the semi-trailer must be registered this is called the registered gross combination mass or RG CM vehicles can be described by the number of axles.
