An add-on load (Beiladung in German) is an extra shipment added to an existing load in free cargo space. It uses spare capacity and earns additional revenue at low extra cost.
Extra cost: detour, extra loading or unloading stop, waiting time and possibly tolls for the detour.
Price: at least these extra costs plus a share of the trip cost by loading metres.
Costing: in Logist Calculator add the stop to the route and compare with the trip without the add-on load.