Frost LSOA mileage pilot v1

Use the source repository accompanying this Site release. Preserve public/research/frost/v1 and the existing traffic archives. No old release file should be changed.

Install Python dependencies: numpy pandas scipy scikit-learn shapely>=2 pyogrio geopandas pyarrow pyproj networkx. Exact used versions are in runtime.json.

Place these original archives in a source directory, checking their full source-register.json hashes:
  os-open-roads-april2026.zip (OS Open Roads April 2026)
  ons-lsoa21-bfc-v10.zip (ONS LSOA2021 EW BFC V10)
  acquisition.json (the newArchives object/list from source-register.json)
The official acquisition URLs are recorded in source-register.json. Never silently use a newer edition if the original hash is unavailable.

From the repository root:
  OPENBLAS_NUM_THREADS=1 OMP_NUM_THREADS=1 python scripts/build-frost-mileage.py --sources /absolute/source-directory --cache /absolute/working-cache
  python scripts/test-frost-mileage.py

Stages prepare, major, model, outcomes and package can be run individually with --stage. Run them in order. The geometry helper scripts/build-frost-features.py must be present. Do not run the build script directly from the public download directory; its root is the parent of scripts/.

The release includes geometry-derived major-section/LSOA allocations, accepted route-link identifiers, minor-fragment lengths and predictions, count matching, holdout predictions, coefficients, exact authority totals and outcome panels. These support numerical auditing without downloading nationwide geometry. Road-link ri and LSOA li are deterministic within this build; li resolves via lsoa-index.csv. OS identifier persistence across editions is not assumed.

The full GIS rebuild still requires the pinned external nationwide archives. Floating-point values may differ in last bits across dependency versions; conservation and inference checks should be compared numerically, not by assuming cross-platform byte-identical CSVs. The manifest verifies this published release's exact bytes.

The assessment amendment records the unavailable new-site 2024 sample and the supplementary geographic holdout. It is part of the protocol. Independent allocation validation has NOT passed.