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Col du Trébatut from Bourgs sur Colagne

9148.8 m · net rise 460.3 m · total ascent 482.1 m · overall 5.0% · evidence quality U (needs confirmation) · Bourgs sur Colagne · Lozère · share

Shape: sustained — 36% of the climbing sits in a quarter of the distance; longest continuous stretch at 10%+ is 28 m.

Not yet matched against documented climbs — the measurement stands on its own.

needs review short window divergence — treat short-window maxima here as provisional.

≈ Overhead cover (tree canopy or structures) spans 14% of this route — detected by comparing the surface model (DSM, treetops and rooftops) against the terrain model (DTM, bare ground). Under cover the bare-ground model is built from fewer laser returns, so metre-scale readings can wobble; maxima whose window sits in a covered zone are marked ≈ below — less certain — the flag does not say whether the true value is higher or lower. Longer windows average over more clean ground and are steadier.

Gradient ladder what do windows mean?

Window	Maximum	Located at
2 m (diagnostic)	≈42%	3610–3612 m	under overhead cover terrain reads 92.0% at 8351–8353 m across a structure — excluded
3 m (diagnostic)	≈27%	3610–3613 m	under overhead cover terrain reads 89.4% at 8350–8353 m across a structure — excluded
5 m	≈29%	3610–3615 m	under overhead cover terrain reads 77.7% at 8349–8354 m across a structure — excluded
10 m	≈20%	3607–3617 m	under overhead cover terrain reads 42.3% at 8349–8359 m across a structure — excluded
20 m	≈12.3%	3607–3627 m	under overhead cover terrain reads 23.3% at 8349–8369 m across a structure — excluded
25 m	≈10.6%	3607–3632 m	under overhead cover terrain reads 19.4% at 8349–8374 m across a structure — excluded
50 m	≈9.9%	2024–2074 m	under overhead cover terrain reads 12.4% at 8349–8399 m across a structure — excluded
100 m	≈9.3%	1971–2071 m	under overhead cover terrain reads 9.7% at 8072–8172 m across a structure — excluded

Map

Check this route yourself: Google Maps route via their router · Street View at the base where coverage exists · geojson.io our exact measured line · OpenTopoMap

This climb's data: OCL JSON — the full gradient ladder, quality flags and provenance in the OpenClimb Ladder format.

Surface: paved throughout, according to BD TOPO®, IGN's national topographic database.

Measured, not vetted. This page records what the laser record shows about the road's shape — nothing more. Nobody has necessarily ridden or inspected this road for the survey, and a page here is not a recommendation and no guarantee that the road is open, surfaced, rideable or safe. Gates, private sections, missing rights of way and hazards do not show up in elevation data. Check access and conditions on the ground and make your own judgment.

Ridden it, or know better? Submit data for this climb no account needed · Share this climb

Route colour = gradient over a 25 m window: <10% 10–20% 20–25% ≥25%

Col du Trébatut from Bourgs sur Colagne LiDAR hillshade map with contours

Profile

The map, profile and gradient chart share one position — move your pointer over them and the marker follows. Colors are the gradient bands; the shaded span is the steepest 25 m. Any 25 m figure is good to about a point either way (why).

Measurement card

Elevation	IGN LiDAR HD MNT 0.5 m — LiDAR HD — MNT (sol) et MNS (surface), 0,50 m (Institut national de l'information géographique et forestière), RGF93 / Lambert-93 EPSG:2154, altitudes IGN69
Resolution / CRS	0.5 m grid, EPSG:2154; sampled every 1.0 m, bilinear interpolation
Tiles	E713-N6380, E713-N6381, E714-N6379, E714-N6380, E714-N6381, E715-N6379, E715-N6380, E716-N6379, E716-N6380, E717-N6379, E718-N6379, E719-N6379, E720-N6379
Road centreline	OpenStreetMap (local PBF extract)
Quality status	evidence quality U; review flags: short window divergence
Analysis	OCL 0.1.0, analysis 0.1.0, run fr-mc5, calculated 2026-09-22

Provenance

{
  "analysis_version": "0.1.0",
  "run_manifest": {
    "manifest_version": "1",
    "code_git_sha": "1cc9fdcd6556a02163cb21acb2293cad3067d2a1",
    "code_git_dirty": "false",
    "analysis_version": "0.1.0",
    "analysis_config_digest": "sha256:8c94015b54267da4",
    "python": "3.14.4",
    "numpy": "2.5.3",
    "rasterio": "1.5.1",
    "pyproj": "3.8.0",
    "laspy": "2.7.0",
    "shapely": "2.1.2",
    "pyosmium": "4.3.1",
    "libosmium": "2.23.1",
    "gdal": "3.12.4",
    "proj": "9.8.1",
    "run_id": "fr-mc5",
    "road_pbf": "block-batch-fr-mc5.osm.pbf",
    "region_key": "france",
    "crs": "EPSG:2154",
    "elevation_provider_key": "ign-lidarhd",
    "tile_index": "wms-grid",
    "authority": "bdtopo",
    "registry_pbf": "france-vosges-2026-09-16.osm.pbf",
    "tile_index_snapshot": "sha256:af4eae1f5df9e232"
  },
  "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:2154",
  "elevation_resolution_m": 0.5,
  "elevation_tiles": [
    "data/cache/fr/ign-lidarhd_dtm_E713-N6380_0m5@21LHD4LO-2024-12-13.tif",
    "data/cache/fr/ign-lidarhd_dtm_E713-N6381_0m5@21LHD4LO-2024-12-13.tif",
    "data/cache/fr/ign-lidarhd_dtm_E714-N6379_0m5@21LHD4LO-2024-12-13.tif",
    "data/cache/fr/ign-lidarhd_dtm_E714-N6380_0m5@21LHD4LO-2024-12-13.tif",
    "data/cache/fr/ign-lidarhd_dtm_E714-N6381_0m5@21LHD4LO-2024-12-13.tif",
    "data/cache/fr/ign-lidarhd_dtm_E715-N6379_0m5@21LHD4LO-2024-12-13.tif",
    "data/cache/fr/ign-lidarhd_dtm_E715-N6380_0m5@21LHD4LO-2024-12-13.tif",
    "data/cache/fr/ign-lidarhd_dtm_E716-N6379_0m5@21LHD4LO-2024-12-13.tif",
    "data/cache/fr/ign-lidarhd_dtm_E716-N6380_0m5@21LHD4LO-2024-12-13.tif",
    "data/cache/fr/ign-lidarhd_dtm_E717-N6379_0m5@21LHD4LO-2024-12-13.tif",
    "data/cache/fr/ign-lidarhd_dtm_E718-N6379_0m5@21LHD4LO-2024-12-13.tif",
    "data/cache/fr/ign-lidarhd_dtm_E719-N6379_0m5@21LHD4LO-2024-12-13.tif",
    "data/cache/fr/ign-lidarhd_dtm_E720-N6379_0m5@21LHD4LO-2024-12-13.tif"
  ],
  "calculated_at": "2026-09-22T16:00:48+00:00",
  "road_source": "OpenStreetMap (local PBF extract)",
  "road_attribution": "\u00a9 OpenStreetMap contributors, ODbL",
  "osm_pbf_path": "data/cache/pbf/block-batch-fr-mc5.osm.pbf",
  "osm_snapshot": "",
  "run_id": "fr-mc5",
  "elevation_provider": "IGN LiDAR HD MNT 0.5 m",
  "elevation_licence": "Licence Ouverte / Open Licence 2.0 (Etalab) \u2014 \u00a9 IGN, LiDAR HD (MNT/MNS), data.geopf.fr; reproduction autoris\u00e9e avec mention de la source et de la date",
  "elevation_dataset": "LiDAR HD \u2014 MNT (sol) et MNS (surface), 0,50 m (Institut national de l'information g\u00e9ographique et foresti\u00e8re), RGF93 / Lambert-93 EPSG:2154, altitudes IGN69",
  "elevation_vertical_datum": "IGN69",
  "elevation_tile_ids": [
    "E713-N6380",
    "E713-N6381",
    "E714-N6379",
    "E714-N6380",
    "E714-N6381",
    "E715-N6379",
    "E715-N6380",
    "E716-N6379",
    "E716-N6380",
    "E717-N6379",
    "E718-N6379",
    "E719-N6379",
    "E720-N6379"
  ],
  "elevation_blocks": [
    "21LHD4LO@2024-12-13"
  ],
  "ign_dalles": [
    "LHD_FXX_0713_6381_MNT_O_0M50_LAMB93_IGN69",
    "LHD_FXX_0713_6382_MNT_O_0M50_LAMB93_IGN69",
    "LHD_FXX_0714_6380_MNT_O_0M50_LAMB93_IGN69",
    "LHD_FXX_0714_6381_MNT_O_0M50_LAMB93_IGN69",
    "LHD_FXX_0714_6382_MNT_O_0M50_LAMB93_IGN69",
    "LHD_FXX_0715_6380_MNT_O_0M50_LAMB93_IGN69",
    "LHD_FXX_0715_6381_MNT_O_0M50_LAMB93_IGN69",
    "LHD_FXX_0716_6380_MNT_O_0M50_LAMB93_IGN69",
    "LHD_FXX_0716_6381_MNT_O_0M50_LAMB93_IGN69",
    "LHD_FXX_0717_6380_MNT_O_0M50_LAMB93_IGN69",
    "LHD_FXX_0718_6380_MNT_O_0M50_LAMB93_IGN69",
    "LHD_FXX_0719_6380_MNT_O_0M50_LAMB93_IGN69",
    "LHD_FXX_0720_6380_MNT_O_0M50_LAMB93_IGN69"
  ],
  "ign_missions": [
    "21LHD4LO"
  ],
  "ign_editions": [
    "2024-12-13"
  ],
  "ign_dsm_edition": {
    "LHD_FXX_0713_6381_MNT_O_0M50_LAMB93_IGN69": "2024-12-13",
    "LHD_FXX_0713_6382_MNT_O_0M50_LAMB93_IGN69": "2024-12-13",
    "LHD_FXX_0714_6380_MNT_O_0M50_LAMB93_IGN69": "2024-12-13",
    "LHD_FXX_0714_6381_MNT_O_0M50_LAMB93_IGN69": "2024-12-13",
    "LHD_FXX_0714_6382_MNT_O_0M50_LAMB93_IGN69": "2024-12-13",
    "LHD_FXX_0715_6380_MNT_O_0M50_LAMB93_IGN69": "2024-12-13",
    "LHD_FXX_0715_6381_MNT_O_0M50_LAMB93_IGN69": "2024-12-13",
    "LHD_FXX_0716_6380_MNT_O_0M50_LAMB93_IGN69": "2024-12-13",
    "LHD_FXX_0716_6381_MNT_O_0M50_LAMB93_IGN69": "2024-12-13",
    "LHD_FXX_0717_6380_MNT_O_0M50_LAMB93_IGN69": "2024-12-13",
    "LHD_FXX_0718_6380_MNT_O_0M50_LAMB93_IGN69": "2024-12-13",
    "LHD_FXX_0719_6380_MNT_O_0M50_LAMB93_IGN69": "2024-12-13",
    "LHD_FXX_0720_6380_MNT_O_0M50_LAMB93_IGN69": "2024-12-13"
  },
  "climb_origin": "named-pass",
  "structure_own_ways": 17,
  "structure_mask_ranges_m": [
    [
      8061.9,
      8077.4
    ]
  ],
  "suppression_unstable": [
    5.0
  ],
  "carriageway": {
    "stations": 372,
    "stations_resolved": 372,
    "width_median_m": 6.5,
    "width_p10_m": 4.5,
    "width_min_m": 1.0,
    "width_max_m": 12.0,
    "bounded_share": 0.403,
    "unbounded_share": 0.597,
    "confidence_median": 0.0,
    "width_median_bounded_m": 6.5,
    "window_m": [
      3607.0,
      3632.0
    ],
    "width_at_max25_m": 2.5,
    "window_stations": 7,
    "single_track": false,
    "single_track_rule": "PROVISIONAL (2026-09-15): width_p10_m <= 3.0 m with bounded_share >= 0.6; recorded, not a rule",
    "status": "ok",
    "source": "dtm",
    "station_m": 25.0,
    "window_station_m": 5.0,
    "halfwidth_m": 6.0,
    "step_m": 0.25,
    "level_tol_m": 0.12,
    "break_min_m": 0.3,
    "stations_failed": 0,
    "hedge_to_hedge": {
      "stations": 372,
      "stations_resolved": 372,
      "width_median_m": 7.62,
      "width_p10_m": 1.25,
      "width_min_m": 0.0,
      "width_max_m": 12.0,
      "bounded_share": 0.715,
      "unbounded_share": 0.285,
      "confidence_median": 1.0,
      "width_median_bounded_m": 6.5,
      "window_m": [
        3607.0,
        3632.0
      ],
      "width_at_max25_m": 5.75,
      "window_stations": 7,
      "status": "ok",
      "source": "dsm",
      "station_m": 25.0,
      "window_station_m": 5.0,
      "halfwidth_m": 6.0,
      "step_m": 0.25,
      "level_tol_m": 0.5,
      "break_min_m": 0.3,
      "stations_failed": 0
    }
  },
  "license": "ODbL-1.0",
  "license_url": "https://howsteep.org/licensing"
}