{
 "ocl_version": "0.1.0",
 "name": "Heywood Street",
 "slug": "heywood-street-2",
 "confidence": "A",
 "reported_claims": [],
 "ladder": [
  {
   "window_m": 2.0,
   "max_gradient_pct": 21.56371360413516,
   "diagnostic": true,
   "flags": [],
   "start_distance_m": 276.0,
   "end_distance_m": 278.0,
   "start_elevation_m": 148.95951428315854,
   "end_elevation_m": 149.39078855524124,
   "min_gradient_pct": -9.2979831619175
  },
  {
   "window_m": 3.0,
   "max_gradient_pct": 21.536959636660907,
   "diagnostic": true,
   "flags": [],
   "start_distance_m": 276.0,
   "end_distance_m": 279.0,
   "start_elevation_m": 148.95951428315854,
   "end_elevation_m": 149.60562307225837,
   "min_gradient_pct": -9.253159718181792
  },
  {
   "window_m": 5.0,
   "max_gradient_pct": 21.516192323599626,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 276.0,
   "end_distance_m": 281.0,
   "start_elevation_m": 148.95951428315854,
   "end_elevation_m": 150.03532389933852,
   "min_gradient_pct": -9.175839212667825
  },
  {
   "window_m": 10.0,
   "max_gradient_pct": 21.287231113404914,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 275.0,
   "end_distance_m": 285.0,
   "start_elevation_m": 148.74669833846102,
   "end_elevation_m": 150.8754214498015,
   "min_gradient_pct": -8.983681476964023
  },
  {
   "window_m": 20.0,
   "max_gradient_pct": 20.916484052184074,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 270.0,
   "end_distance_m": 290.0,
   "start_elevation_m": 147.7231604612749,
   "end_elevation_m": 151.9064572717117,
   "min_gradient_pct": -8.766547824209283
  },
  {
   "window_m": 25.0,
   "max_gradient_pct": 20.680249033677796,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 267.0,
   "end_distance_m": 292.0,
   "start_elevation_m": 147.14073846019448,
   "end_elevation_m": 152.31080071861393,
   "min_gradient_pct": -8.724628865635168
  },
  {
   "window_m": 50.0,
   "max_gradient_pct": 18.300200766251407,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 249.0,
   "end_distance_m": 299.0,
   "start_elevation_m": 144.30620706009014,
   "end_elevation_m": 153.45630744321585,
   "min_gradient_pct": -7.764222060001828
  },
  {
   "window_m": 100.0,
   "max_gradient_pct": 13.208857338841566,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 200.0,
   "end_distance_m": 300.0,
   "start_elevation_m": 140.34133814013555,
   "end_elevation_m": 153.55019547897712,
   "min_gradient_pct": -3.5856290043811896
  }
 ],
 "shape": {
  "ascent_concentration": 0.365,
  "concentration_window_frac": 0.25,
  "longest_pitch_10pct_m": 60.0,
  "shape_class": "sustained"
 },
 "length_m": 1282.1841558381334,
 "start_elevation_m": 130.39606495886022,
 "end_elevation_m": 192.48958427929995,
 "endpoint_gain_m": 62.093519320439725,
 "overall_gradient_pct": 4.842792592445558,
 "accumulated_ascent_m": 66.63429318703652,
 "window_maxima": {
  "max_5m": {
   "gradient_pct": 21.516192323599626,
   "start_distance_m": 276.0,
   "end_distance_m": 281.0,
   "midpoint_distance_m": 278.5,
   "start_elevation_m": 148.95951428315854,
   "end_elevation_m": 150.03532389933852,
   "start_xy": [
    270937.1187077984,
    4717160.783515012
   ],
   "end_xy": [
    270932.4331837132,
    4717159.038274613
   ]
  },
  "max_10m": {
   "gradient_pct": 21.287231113404914,
   "start_distance_m": 275.0,
   "end_distance_m": 285.0,
   "midpoint_distance_m": 280.0,
   "start_elevation_m": 148.74669833846102,
   "end_elevation_m": 150.8754214498015,
   "start_xy": [
    270938.0558126155,
    4717161.132563091
   ],
   "end_xy": [
    270928.684764445,
    4717157.642082295
   ]
  },
  "max_20m": {
   "gradient_pct": 20.916484052184074,
   "start_distance_m": 270.0,
   "end_distance_m": 290.0,
   "midpoint_distance_m": 280.0,
   "start_elevation_m": 147.7231604612749,
   "end_elevation_m": 151.9064572717117,
   "start_xy": [
    270942.7413367007,
    4717162.877803489
   ],
   "end_xy": [
    270923.99924035976,
    4717155.896841898
   ]
  },
  "max_25m": {
   "gradient_pct": 20.680249033677796,
   "start_distance_m": 267.0,
   "end_distance_m": 292.0,
   "midpoint_distance_m": 279.5,
   "start_elevation_m": 147.14073846019448,
   "end_elevation_m": 152.31080071861393,
   "start_xy": [
    270945.55265115184,
    4717163.9249477275
   ],
   "end_xy": [
    270922.12503072567,
    4717155.198745738
   ]
  },
  "max_50m": {
   "gradient_pct": 18.300200766251407,
   "start_distance_m": 249.0,
   "end_distance_m": 299.0,
   "midpoint_distance_m": 274.0,
   "start_elevation_m": 144.30620706009014,
   "end_elevation_m": 153.45630744321585,
   "start_xy": [
    270962.4205378587,
    4717170.2078131605
   ],
   "end_xy": [
    270915.5792369479,
    4717152.71862574
   ]
  },
  "max_100m": {
   "gradient_pct": 13.208857338841566,
   "start_distance_m": 200.0,
   "end_distance_m": 300.0,
   "midpoint_distance_m": 250.0,
   "start_elevation_m": 140.34133814013555,
   "end_elevation_m": 153.55019547897712,
   "start_xy": [
    270970.7694164949,
    4717204.080244631
   ],
   "end_xy": [
    270914.6461680854,
    4717152.358927953
   ]
  }
 },
 "window_minima": {
  "min_5m": {
   "gradient_pct": -9.175839212667825,
   "start_distance_m": 926.0,
   "end_distance_m": 931.0,
   "midpoint_distance_m": 928.5,
   "start_elevation_m": 182.33684744063515,
   "end_elevation_m": 181.87805548000176,
   "start_xy": [
    270496.30838365736,
    4716758.8838062715
   ],
   "end_xy": [
    270493.491338545,
    4716754.753506724
   ]
  },
  "min_10m": {
   "gradient_pct": -8.983681476964023,
   "start_distance_m": 922.0,
   "end_distance_m": 932.0,
   "midpoint_distance_m": 927.0,
   "start_elevation_m": 182.68787345689495,
   "end_elevation_m": 181.78950530919855,
   "start_xy": [
    270498.58112741966,
    4716762.175407066
   ],
   "end_xy": [
    270492.9563701295,
    4716753.908634666
   ]
  },
  "min_20m": {
   "gradient_pct": -8.766547824209283,
   "start_distance_m": 916.0,
   "end_distance_m": 936.0,
   "midpoint_distance_m": 926.0,
   "start_elevation_m": 183.20502354532607,
   "end_elevation_m": 181.45171398048421,
   "start_xy": [
    270501.99024306313,
    4716767.112808257
   ],
   "end_xy": [
    270490.8164964674,
    4716750.529146434
   ]
  },
  "min_25m": {
   "gradient_pct": -8.724628865635168,
   "start_distance_m": 915.0,
   "end_distance_m": 940.0,
   "midpoint_distance_m": 927.5,
   "start_elevation_m": 183.29106777394358,
   "end_elevation_m": 181.1099105575348,
   "start_xy": [
    270502.5584290037,
    4716767.935708457
   ],
   "end_xy": [
    270488.6766228053,
    4716747.149658202
   ]
  },
  "min_50m": {
   "gradient_pct": -7.764222060001828,
   "start_distance_m": 901.0,
   "end_distance_m": 951.0,
   "midpoint_distance_m": 926.0,
   "start_elevation_m": 184.210419877259,
   "end_elevation_m": 180.32830884725809,
   "start_xy": [
    270510.51303217176,
    4716779.456311237
   ],
   "end_xy": [
    270482.7968966626,
    4716737.85295415
   ]
  },
  "min_100m": {
   "gradient_pct": -3.5856290043811896,
   "start_distance_m": 864.0,
   "end_distance_m": 964.0,
   "midpoint_distance_m": 914.0,
   "start_elevation_m": 184.0649746953549,
   "end_elevation_m": 180.4793456909737,
   "start_xy": [
    270531.4698780389,
    4716809.948560756
   ],
   "end_xy": [
    270484.24890436104,
    4716727.939532623
   ]
  }
 },
 "diagnostic_window_maxima": {
  "max_2m": {
   "gradient_pct": 21.56371360413516,
   "start_distance_m": 276.0,
   "end_distance_m": 278.0,
   "midpoint_distance_m": 277.0,
   "start_elevation_m": 148.95951428315854,
   "end_elevation_m": 149.39078855524124,
   "start_xy": [
    270937.1187077984,
    4717160.783515012
   ],
   "end_xy": [
    270935.24449816433,
    4717160.085418852
   ]
  },
  "max_3m": {
   "gradient_pct": 21.536959636660907,
   "start_distance_m": 276.0,
   "end_distance_m": 279.0,
   "midpoint_distance_m": 277.5,
   "start_elevation_m": 148.95951428315854,
   "end_elevation_m": 149.60562307225837,
   "start_xy": [
    270937.1187077984,
    4717160.783515012
   ],
   "end_xy": [
    270934.30739334726,
    4717159.736370773
   ]
  }
 },
 "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": []
 },
 "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/ma-east/USGS_1M_19_x27y472_MA_CentralEastern_2021_B21.tif"
  ],
  "calculated_at": "2026-08-24T21:35:15+00:00",
  "road_source": "OpenStreetMap (local PBF extract)",
  "road_attribution": "\u00a9 OpenStreetMap contributors, ODbL",
  "osm_pbf_path": "data/cache/pbf/massachusetts-260822.osm.pbf",
  "osm_snapshot": "2026-08-21T20:21:11Z",
  "run_id": "redo-ma-6-260824",
  "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, MA_CentralEastern_2021_B21 (collected 2021)",
  "elevation_tile_ids": [
   "x27y472"
  ],
  "climb_origin": "discovered",
  "notes": "Coarse pass: max 7.6% over 200 m (Terrain 50), gain 25.7 m over 626 m way. EXTENDED by graph walk: +6 segment(s) at base, +2 at top (stop: base=no_descending_continuation, top=no_ascending_continuation; min_avg=2.0%). Review before adopting. ADOPTED (NE wave 1, 2026-08-25): clean-steep. 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": "Fitchburg",
  "county": "Massachusetts"
 }
}