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  "road_source": "OpenStreetMap (local PBF extract)",
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  "osm_snapshot": "2026-08-10T20:21:40Z",
  "elevation_provider": "Welsh Government",
  "elevation_dataset": "Welsh Government LiDAR 1m DTM (2020-2023)",
  "elevation_licence": "Open Government Licence v3 \u2014 \u00a9 Crown copyright Welsh Government",
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  "notes": "Coarse pass: max 15.6% over 200 m (Terrain 50), gain 83.1 m over 625 m way. EXTENDED by graph walk: +0 segment(s) at base, +2 at top (stop: base=no_descending_continuation, top=no_ascending_continuation; min_avg=2.0%). Review before adopting. ADOPTED (notable slice 2026-08-11): clean-steep."
 },
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  "county": "Sir Ceredigion - Ceredigion"
 },
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}