Drone or Porter on a Hill Path? A Distance Crossover for Light, Urgent Postal Loads

For light urgent loads — medicines, documents, blood samples, a single critical parcel — hill settlements are served either by a porter on a path or, increasingly, by a small drone. This paper compares the two on stated costs: a porter paid USD 1.20 per hour walking at 3 km/h loaded and 4 km/h returning, against a drone cruising at 40 km/h whose capital, battery and maintenance costs are spread over eight trips a day. The drone becomes the cheaper mode per trip beyond a one-way distance of 6.5 km. At 15 km the porter costs USD 10.5 per round trip and manages 1.0 trips a day; the drone costs USD 5.06 and manages 10.6. But the crossover holds only inside the drone's 3 kg payload: a porter carries 15 kg, so for loads above 3 kg the comparison does not arise at any distance. The claim that drones replace porters on hill routes is therefore true only in a band — light loads, longer paths, high trip counts — and false outside it. SIMULATED, NOT MEASURED.