Assigned vehicles will be allocated to transfer cargo exclusively for this building. This means that anytime an assigned vehicle performs a delivery this building has to be either source or destination of the cargo. This can be combined with routes assignment to form dedicated supply lines.
tooltip that explains what trucks do when assigned to a general building (e.g. storage)
Assigned trucks will follow this harvester which will load them with wood. Trucks will deliver the wood to the factory and return back to the harvester.