Why would you use drones for this when you can build a very small rail network? Drones can't carry very much, and they can have problems in flight that will lead to dropped/damaged goods, not to mention they'll require more energy. A small rail network could transport the same small goods over the same areas with less energy and no potential dropped/damaged goods.
Their aerial route should ideally not go over forested or ecologically sensitive areas, in part to avoid contamination from crashed drones, and in part because drones push birds out of their nesting and feeding grounds, and territorial birds actively fight small drones.
Their aerial route should ideally not go over forested or ecologically sensitive areas, in part to avoid contamination from crashed drones, and in part because drones push birds out of their nesting and feeding grounds, and territorial birds actively fight small drones.