The size of the vessel of a dump truck is determined according to the capacity of each truck. If you overload its capacity, it may not be able to run or would spill soil, sand, etc. If under-loaded, it increases the number of trips needed and impacts productivity and cost. As a solution, dump trucks come with a lamp called the “payload meter” which measures the load capacity as it is being loaded. Thanks to this lamp, workers know exactly when to stop loading.