{
 "ocl_version": "0.1.0",
 "name": "Webster Road",
 "slug": "webster-road",
 "confidence": "A",
 "reported_claims": [],
 "ladder": [
  {
   "window_m": 2.0,
   "max_gradient_pct": 37.81877551595585,
   "diagnostic": true,
   "flags": [],
   "start_distance_m": 781.0,
   "end_distance_m": 783.0,
   "start_elevation_m": 357.9493135429965,
   "end_elevation_m": 358.7056890533156,
   "min_gradient_pct": -16.172438381170195
  },
  {
   "window_m": 3.0,
   "max_gradient_pct": 29.643102659118387,
   "diagnostic": true,
   "flags": [],
   "start_distance_m": 781.0,
   "end_distance_m": 784.0,
   "start_elevation_m": 357.9493135429965,
   "end_elevation_m": 358.83860662277004,
   "min_gradient_pct": -14.346200944657994
  },
  {
   "window_m": 5.0,
   "max_gradient_pct": 26.344740469772887,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 941.0,
   "end_distance_m": 946.0,
   "start_elevation_m": 375.00756815641574,
   "end_elevation_m": 376.3248051799044,
   "min_gradient_pct": -12.39310865124935
  },
  {
   "window_m": 10.0,
   "max_gradient_pct": 24.115632754796934,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 941.0,
   "end_distance_m": 951.0,
   "start_elevation_m": 375.00756815641574,
   "end_elevation_m": 377.41913143189544,
   "min_gradient_pct": -11.640696210193937
  },
  {
   "window_m": 20.0,
   "max_gradient_pct": 20.944944559943508,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 937.0,
   "end_distance_m": 957.0,
   "start_elevation_m": 374.25699857763726,
   "end_elevation_m": 378.44598748962596,
   "min_gradient_pct": -9.559695983981555
  },
  {
   "window_m": 25.0,
   "max_gradient_pct": 19.131539562065882,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 937.0,
   "end_distance_m": 962.0,
   "start_elevation_m": 374.25699857763726,
   "end_elevation_m": 379.03988346815373,
   "min_gradient_pct": -8.511045223987367
  },
  {
   "window_m": 50.0,
   "max_gradient_pct": 17.509043636620277,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 534.0,
   "end_distance_m": 584.0,
   "start_elevation_m": 329.08743621076286,
   "end_elevation_m": 337.841958029073,
   "min_gradient_pct": -5.317077788265351
  },
  {
   "window_m": 100.0,
   "max_gradient_pct": 15.398760569420972,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 528.0,
   "end_distance_m": 628.0,
   "start_elevation_m": 328.2759110853303,
   "end_elevation_m": 343.67467165475125,
   "min_gradient_pct": -3.8456981889643203
  }
 ],
 "shape": {
  "ascent_concentration": 0.473,
  "concentration_window_frac": 0.25,
  "longest_pitch_10pct_m": 289.0,
  "shape_class": "stepped"
 },
 "length_m": 4595.6657369935365,
 "start_elevation_m": 274.77352923581304,
 "end_elevation_m": 562.093341062924,
 "endpoint_gain_m": 287.3198118271109,
 "overall_gradient_pct": 6.251973669762028,
 "accumulated_ascent_m": 304.5691681853561,
 "window_maxima": {
  "max_5m": {
   "gradient_pct": 26.344740469772887,
   "start_distance_m": 941.0,
   "end_distance_m": 946.0,
   "midpoint_distance_m": 943.5,
   "start_elevation_m": 375.00756815641574,
   "end_elevation_m": 376.3248051799044,
   "start_xy": [
    648410.6262187627,
    4679478.697307704
   ],
   "end_xy": [
    648415.6093172075,
    4679479.108075144
   ]
  },
  "max_10m": {
   "gradient_pct": 24.115632754796934,
   "start_distance_m": 941.0,
   "end_distance_m": 951.0,
   "midpoint_distance_m": 946.0,
   "start_elevation_m": 375.00756815641574,
   "end_elevation_m": 377.41913143189544,
   "start_xy": [
    648410.6262187627,
    4679478.697307704
   ],
   "end_xy": [
    648420.5979740298,
    4679479.441982035
   ]
  },
  "max_20m": {
   "gradient_pct": 20.944944559943508,
   "start_distance_m": 937.0,
   "end_distance_m": 957.0,
   "midpoint_distance_m": 947.0,
   "start_elevation_m": 374.25699857763726,
   "end_elevation_m": 378.44598748962596,
   "start_xy": [
    648406.6387737128,
    4679478.381324673
   ],
   "end_xy": [
    648426.5863944191,
    4679479.814569261
   ]
  },
  "max_25m": {
   "gradient_pct": 19.131539562065882,
   "start_distance_m": 937.0,
   "end_distance_m": 962.0,
   "midpoint_distance_m": 949.5,
   "start_elevation_m": 374.25699857763726,
   "end_elevation_m": 379.03988346815373,
   "start_xy": [
    648406.6387737128,
    4679478.381324673
   ],
   "end_xy": [
    648431.5760462565,
    4679480.135589422
   ]
  },
  "max_50m": {
   "gradient_pct": 17.509043636620277,
   "start_distance_m": 534.0,
   "end_distance_m": 584.0,
   "midpoint_distance_m": 559.0,
   "start_elevation_m": 329.08743621076286,
   "end_elevation_m": 337.841958029073,
   "start_xy": [
    648048.1086155422,
    4679570.361447585
   ],
   "end_xy": [
    648097.34089757,
    4679578.778349307
   ]
  },
  "max_100m": {
   "gradient_pct": 15.398760569420972,
   "start_distance_m": 528.0,
   "end_distance_m": 628.0,
   "midpoint_distance_m": 578.0,
   "start_elevation_m": 328.2759110853303,
   "end_elevation_m": 343.67467165475125,
   "start_xy": [
    648042.1324609815,
    4679569.833061974
   ],
   "end_xy": [
    648139.9236854883,
    4679589.817201287
   ]
  }
 },
 "window_minima": {
  "min_5m": {
   "gradient_pct": -12.39310865124935,
   "start_distance_m": 3981.0,
   "end_distance_m": 3986.0,
   "midpoint_distance_m": 3983.5,
   "start_elevation_m": 540.3842054522546,
   "end_elevation_m": 539.7645500196921,
   "start_xy": [
    651076.3587905132,
    4678995.481586367
   ],
   "end_xy": [
    651081.3415747155,
    4678995.613693328
   ]
  },
  "min_10m": {
   "gradient_pct": -11.640696210193937,
   "start_distance_m": 3978.0,
   "end_distance_m": 3988.0,
   "midpoint_distance_m": 3983.0,
   "start_elevation_m": 540.7156507372505,
   "end_elevation_m": 539.5515811162311,
   "start_xy": [
    651073.3762635456,
    4678995.804901827
   ],
   "end_xy": [
    651083.3363212933,
    4678995.758559093
   ]
  },
  "min_20m": {
   "gradient_pct": -9.559695983981555,
   "start_distance_m": 3975.0,
   "end_distance_m": 3995.0,
   "midpoint_distance_m": 3985.0,
   "start_elevation_m": 540.9213647727859,
   "end_elevation_m": 539.0094255759896,
   "start_xy": [
    651070.4473140469,
    4678996.424215564
   ],
   "end_xy": [
    651090.3169059814,
    4678996.279055948
   ]
  },
  "min_25m": {
   "gradient_pct": -8.511045223987367,
   "start_distance_m": 3975.0,
   "end_distance_m": 4000.0,
   "midpoint_distance_m": 3987.5,
   "start_elevation_m": 540.9213647727859,
   "end_elevation_m": 538.793603466789,
   "start_xy": [
    651070.4473140469,
    4678996.424215564
   ],
   "end_xy": [
    651095.3009422095,
    4678996.6782837985
   ]
  },
  "min_50m": {
   "gradient_pct": -5.317077788265351,
   "start_distance_m": 3973.0,
   "end_distance_m": 4023.0,
   "midpoint_distance_m": 3998.0,
   "start_elevation_m": 540.978260515674,
   "end_elevation_m": 538.3197216215414,
   "start_xy": [
    651068.5095648735,
    4678996.919319735
   ],
   "end_xy": [
    651118.2238968833,
    4678998.558696717
   ]
  },
  "min_100m": {
   "gradient_pct": -3.8456981889643203,
   "start_distance_m": 3437.0,
   "end_distance_m": 3537.0,
   "midpoint_distance_m": 3487.0,
   "start_elevation_m": 542.7198288229766,
   "end_elevation_m": 538.8741306340123,
   "start_xy": [
    650641.864203826,
    4679315.564020392
   ],
   "end_xy": [
    650726.5783140915,
    4679262.438563446
   ]
  }
 },
 "diagnostic_window_maxima": {
  "max_2m": {
   "gradient_pct": 37.81877551595585,
   "start_distance_m": 781.0,
   "end_distance_m": 783.0,
   "midpoint_distance_m": 782.0,
   "start_elevation_m": 357.9493135429965,
   "end_elevation_m": 358.7056890533156,
   "start_xy": [
    648272.9363816553,
    4679542.506685732
   ],
   "end_xy": [
    648274.5048557654,
    4679541.265763105
   ]
  },
  "max_3m": {
   "gradient_pct": 29.643102659118387,
   "start_distance_m": 781.0,
   "end_distance_m": 784.0,
   "midpoint_distance_m": 782.5,
   "start_elevation_m": 357.9493135429965,
   "end_elevation_m": 358.83860662277004,
   "start_xy": [
    648272.9363816553,
    4679542.506685732
   ],
   "end_xy": [
    648275.2890928205,
    4679540.645301791
   ]
  }
 },
 "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": [
   "may_start_earlier"
  ]
 },
 "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:26918",
  "elevation_resolution_m": 1.0,
  "elevation_tiles": [
   "data/cache/usa/ma/USGS_1M_18_x64y468_MA_Western_B24.tif",
   "data/cache/usa/ma/USGS_1M_18_x65y468_MA_Western_B24.tif"
  ],
  "calculated_at": "2026-08-24T21:30:24+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-3-260824",
  "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_Western_B24 (collected 2023-24)",
  "elevation_tile_ids": [
   "x64y468",
   "x65y468"
  ],
  "climb_origin": "discovered",
  "notes": "Coarse pass: max 10.5% over 200 m (Terrain 50), gain 132.0 m over 3219 m way. EXTENDED by graph walk: +3 segment(s) at base, +0 at top (stop: base=no_descending_continuation, top=no_ascending_continuation; min_avg=2.0%). Review before adopting. DEDUPE: absorbed 2 overlapping proposal(s): discovered-lane-42-2554-73-2034, webster-road 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": "Tyringham",
  "county": "Massachusetts"
 }
}