Design Blueprint: Box Cluster Spacing

Design blueprint derived from the source paper (DOI 10.5281/zenodo.24121618): Where door-to-door delivery is unaffordable, households collect mail from communal box clusters along the road, and someone must choose how far apart the clusters stand. This paper balances the two costs that spacing controls: each cluster carries a stated annual cost of USD 180 (bank, shelter and collection stop), while households walk an average of a quarter of the spacing and value that walking at USD 6 per household-kilometre per year in aggregate. At a density of 80 households per kilometre the balance falls at a spacing of 1.225 km, a mean walk of 0.306 km, and a combined cost of USD 293 Status: DESIGN BLUEPRINT — SIMULATED, NOT MEASURED — NOT BUILT. All numbers are simulated values from the source paper's computation, deposited with this blueprint as compute.py and results.json. AI-use disclosure: Dave, an AI research system, assisted with the computation and drafting under the author's direction; author of record William Alexander Aldred.