{
 "ocl_version": "0.1.0",
 "name": "Harkney Hill Road",
 "slug": "harkney-hill-road",
 "confidence": "A",
 "reported_claims": [],
 "ladder": [
  {
   "window_m": 2.0,
   "max_gradient_pct": 13.001085683079339,
   "diagnostic": true,
   "flags": [],
   "start_distance_m": 1672.0,
   "end_distance_m": 1674.0,
   "start_elevation_m": 109.74328646474582,
   "end_elevation_m": 110.00330817840741,
   "min_gradient_pct": -7.055724413199016
  },
  {
   "window_m": 3.0,
   "max_gradient_pct": 12.934751398267016,
   "diagnostic": true,
   "flags": [],
   "start_distance_m": 1670.0,
   "end_distance_m": 1673.0,
   "start_elevation_m": 109.48383688222421,
   "end_elevation_m": 109.87187942417222,
   "min_gradient_pct": -6.987368508761922
  },
  {
   "window_m": 5.0,
   "max_gradient_pct": 12.802231224661114,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 1669.0,
   "end_distance_m": 1674.0,
   "start_elevation_m": 109.36319661717435,
   "end_elevation_m": 110.00330817840741,
   "min_gradient_pct": -6.7417780872136746
  },
  {
   "window_m": 10.0,
   "max_gradient_pct": 12.521962559154929,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 1665.0,
   "end_distance_m": 1675.0,
   "start_elevation_m": 108.87163411999636,
   "end_elevation_m": 110.12383037591185,
   "min_gradient_pct": -6.620732519175192
  },
  {
   "window_m": 20.0,
   "max_gradient_pct": 12.242302721045917,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 1662.0,
   "end_distance_m": 1682.0,
   "start_elevation_m": 108.51413914342868,
   "end_elevation_m": 110.96259968763786,
   "min_gradient_pct": -6.519086645326411
  },
  {
   "window_m": 25.0,
   "max_gradient_pct": 12.169177372992522,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 1731.0,
   "end_distance_m": 1756.0,
   "start_elevation_m": 116.80779944442543,
   "end_elevation_m": 119.85009378767356,
   "min_gradient_pct": -6.494684764360159
  },
  {
   "window_m": 50.0,
   "max_gradient_pct": 12.120714643537527,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 1699.0,
   "end_distance_m": 1749.0,
   "start_elevation_m": 112.94436311785314,
   "end_elevation_m": 119.0047204396219,
   "min_gradient_pct": -6.139373517957665
  },
  {
   "window_m": 100.0,
   "max_gradient_pct": 12.067280094219015,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 1664.0,
   "end_distance_m": 1764.0,
   "start_elevation_m": 108.75521733942861,
   "end_elevation_m": 120.82249743364763,
   "min_gradient_pct": -5.502281734169117
  }
 ],
 "shape": {
  "ascent_concentration": 0.533,
  "concentration_window_frac": 0.25,
  "longest_pitch_10pct_m": 223.0,
  "shape_class": "stepped"
 },
 "length_m": 5663.139369375542,
 "start_elevation_m": 87.0864368896184,
 "end_elevation_m": 167.04824859008818,
 "endpoint_gain_m": 79.96181170046978,
 "overall_gradient_pct": 1.411969695340324,
 "accumulated_ascent_m": 119.44544508101384,
 "window_maxima": {
  "max_5m": {
   "gradient_pct": 12.802231224661114,
   "start_distance_m": 1669.0,
   "end_distance_m": 1674.0,
   "midpoint_distance_m": 1671.5,
   "start_elevation_m": 109.36319661717435,
   "end_elevation_m": 110.00330817840741,
   "start_xy": [
    279977.4609288753,
    4616991.99856175
   ],
   "end_xy": [
    279972.6595303095,
    4616993.393757726
   ]
  },
  "max_10m": {
   "gradient_pct": 12.521962559154929,
   "start_distance_m": 1665.0,
   "end_distance_m": 1675.0,
   "midpoint_distance_m": 1670.0,
   "start_elevation_m": 108.87163411999636,
   "end_elevation_m": 110.12383037591185,
   "start_xy": [
    279981.302047728,
    4616990.882404969
   ],
   "end_xy": [
    279971.70001443115,
    4616993.675325324
   ]
  },
  "max_20m": {
   "gradient_pct": 12.242302721045917,
   "start_distance_m": 1662.0,
   "end_distance_m": 1682.0,
   "midpoint_distance_m": 1672.0,
   "start_elevation_m": 108.51413914342868,
   "end_elevation_m": 110.96259968763786,
   "start_xy": [
    279984.1878695478,
    4616990.064117763
   ],
   "end_xy": [
    279965.02093319246,
    4616995.770527894
   ]
  },
  "max_25m": {
   "gradient_pct": 12.169177372992522,
   "start_distance_m": 1731.0,
   "end_distance_m": 1756.0,
   "midpoint_distance_m": 1743.5,
   "start_elevation_m": 116.80779944442543,
   "end_elevation_m": 119.85009378767356,
   "start_xy": [
    279918.1338391032,
    4617009.8998832805
   ],
   "end_xy": [
    279894.4184718626,
    4617017.801794987
   ]
  },
  "max_50m": {
   "gradient_pct": 12.120714643537527,
   "start_distance_m": 1699.0,
   "end_distance_m": 1749.0,
   "midpoint_distance_m": 1724.0,
   "start_elevation_m": 112.94436311785314,
   "end_elevation_m": 119.0047204396219,
   "start_xy": [
    279948.63672065776,
    4617000.281346108
   ],
   "end_xy": [
    279901.036894132,
    4617015.522214617
   ]
  },
  "max_100m": {
   "gradient_pct": 12.067280094219015,
   "start_distance_m": 1664.0,
   "end_distance_m": 1764.0,
   "midpoint_distance_m": 1714.0,
   "start_elevation_m": 108.75521733942861,
   "end_elevation_m": 120.82249743364763,
   "start_xy": [
    279982.26232744113,
    4616990.603365773
   ],
   "end_xy": [
    279886.85456069757,
    4617020.407029696
   ]
  }
 },
 "window_minima": {
  "min_5m": {
   "gradient_pct": -6.7417780872136746,
   "start_distance_m": 2225.0,
   "end_distance_m": 2230.0,
   "midpoint_distance_m": 2227.5,
   "start_elevation_m": 135.9775217517025,
   "end_elevation_m": 135.64043284734183,
   "start_xy": [
    279450.7762405134,
    4617169.7668581735
   ],
   "end_xy": [
    279446.0533756335,
    4617171.407778115
   ]
  },
  "min_10m": {
   "gradient_pct": -6.620732519175192,
   "start_distance_m": 2218.0,
   "end_distance_m": 2228.0,
   "midpoint_distance_m": 2223.0,
   "start_elevation_m": 136.42997394835717,
   "end_elevation_m": 135.76790069643965,
   "start_xy": [
    279457.4217355681,
    4617167.56745019
   ],
   "end_xy": [
    279447.93914152135,
    4617170.741529651
   ]
  },
  "min_20m": {
   "gradient_pct": -6.519086645326411,
   "start_distance_m": 2217.0,
   "end_distance_m": 2237.0,
   "midpoint_distance_m": 2227.0,
   "start_elevation_m": 136.49376353819585,
   "end_elevation_m": 135.18994620913057,
   "start_xy": [
    279458.37109200447,
    4617167.253249049
   ],
   "end_xy": [
    279439.453195026,
    4617173.7396477405
   ]
  },
  "min_25m": {
   "gradient_pct": -6.494684764360159,
   "start_distance_m": 2212.0,
   "end_distance_m": 2237.0,
   "midpoint_distance_m": 2224.5,
   "start_elevation_m": 136.8136174002206,
   "end_elevation_m": 135.18994620913057,
   "start_xy": [
    279463.11787418637,
    4617165.682243347
   ],
   "end_xy": [
    279439.453195026,
    4617173.7396477405
   ]
  },
  "min_50m": {
   "gradient_pct": -6.139373517957665,
   "start_distance_m": 2188.0,
   "end_distance_m": 2238.0,
   "midpoint_distance_m": 2213.0,
   "start_elevation_m": 138.19696000302042,
   "end_elevation_m": 135.1272732440416,
   "start_xy": [
    279485.9024286594,
    4617158.141415974
   ],
   "end_xy": [
    279438.5103120821,
    4617174.072771972
   ]
  },
  "min_100m": {
   "gradient_pct": -5.502281734169117,
   "start_distance_m": 2168.0,
   "end_distance_m": 2268.0,
   "midpoint_distance_m": 2218.0,
   "start_elevation_m": 139.08839280351788,
   "end_elevation_m": 133.58611106934876,
   "start_xy": [
    279504.8179356669,
    4617151.651469781
   ],
   "end_xy": [
    279410.2238237643,
    4617184.066498937
   ]
  }
 },
 "diagnostic_window_maxima": {
  "max_2m": {
   "gradient_pct": 13.001085683079339,
   "start_distance_m": 1672.0,
   "end_distance_m": 1674.0,
   "midpoint_distance_m": 1673.0,
   "start_elevation_m": 109.74328646474582,
   "end_elevation_m": 110.00330817840741,
   "start_xy": [
    279974.5800897358,
    4616992.8356793355
   ],
   "end_xy": [
    279972.6595303095,
    4616993.393757726
   ]
  },
  "max_3m": {
   "gradient_pct": 12.934751398267016,
   "start_distance_m": 1670.0,
   "end_distance_m": 1673.0,
   "midpoint_distance_m": 1671.5,
   "start_elevation_m": 109.48383688222421,
   "end_elevation_m": 109.87187942417222,
   "start_xy": [
    279976.50064916216,
    4616992.277600945
   ],
   "end_xy": [
    279973.61981002265,
    4616993.11471853
   ]
  }
 },
 "diagnostic_note": "Windows <=3 m are at raster-noise scale (1-sigma raster noise alone is roughly +/-7 pp at 2 m and +/-5 pp at 3 m on a 1 m DTM). Diagnostic use only: never a headline or ranking value.",
 "quality_summary": {
  "review": [],
  "extent": [
   "descends_at_start"
  ]
 },
 "provenance": {
  "analysis_version": "0.1.0",
  "sample_interval_m": 1.0,
  "interpolation": "bilinear",
  "smoothing": "none",
  "gradient_windows_m": [
   5.0,
   10.0,
   20.0,
   25.0,
   50.0,
   100.0
  ],
  "diagnostic_windows_m": [
   2.0,
   3.0
  ],
  "elevation_crs": "EPSG:26919",
  "elevation_resolution_m": 1.0,
  "elevation_tiles": [
   "data/cache/usa/ri/USGS_1M_19_x27y462_RI_Statewide_D22.tif",
   "data/cache/usa/ri/USGS_1M_19_x28y462_RI_Statewide_D22.tif"
  ],
  "calculated_at": "2026-08-24T22:24:08+00:00",
  "road_source": "OpenStreetMap (local PBF extract)",
  "road_attribution": "\u00a9 OpenStreetMap contributors, ODbL",
  "osm_pbf_path": "data/cache/pbf/rhode-island-2026-08-23.osm.pbf",
  "osm_snapshot": "2026-08-22T20:21:28Z",
  "run_id": "redo-ri-1-260824",
  "elevation_provider": "USGS 3DEP (The National Map)",
  "elevation_licence": "Public domain \u2014 USGS 3DEP 1 m DEM, courtesy of the U.S. Geological Survey",
  "elevation_dataset": "USGS 3DEP 1 m DEM, RI_Statewide_D22 (collected 2022)",
  "elevation_tile_ids": [
   "x27y462",
   "x28y462"
  ],
  "climb_origin": "discovered",
  "notes": "Coarse pass: max 11.9% over 200 m (Terrain 50), gain 80.2 m over 5663 m way. KEPT at seed extent: no ascending continuation (min_avg=2.0%). ADOPTED (NE wave 1, 2026-08-25): big-gain. Wales dials per PRODUCTION 'US ADOPTION DIALS'.",
  "canopy_check": "unavailable \u2014 no surface model (DSM or point cloud) registered for this coverage",
  "license": "ODbL-1.0",
  "license_url": "https://howsteep.org/licensing.html"
 },
 "area": {
  "place": "Coventry",
  "county": "Rhode Island"
 }
}