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  "road_source": "OpenStreetMap (local PBF extract)",
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  "elevation_provider": "Environment Agency",
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  "notes": "Coarse pass: max 14.6% over 200 m (Terrain 50), gain 178.0 m over 2670 m way. EXTENDED by graph walk: +1 segment(s) at base, +1 at top (stop: base=no_descending_continuation, top=no_ascending_continuation; min_avg=2.0%). Review before adopting. DEDUPE: absorbed 1 overlapping proposal(s): discovered-lane-51-0524-3-5638 ADOPTED (England launch slice 2026-08-16): clean-steep."
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}