LIVING SURVEY — measurements are reviewed continuously as new data and local evidence arrive. Seen a sign, a gate, or a better name? Submit an update no account needed · photos welcome via GitHub

← all climbs

Le Mauvais Pas from Pian del Colle

4235.3 m · net rise 299.6 m · total ascent 345.8 m · overall 7.1% · evidence quality B (good) · Bardonecchia · Hautes-Alpes ·

Shape: sustained — 31% of the climbing sits in a quarter of the distance; longest continuous stretch at 10%+ is 177 m.

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

Gradient ladder what do windows mean?

WindowMaximumLocated at
2 m (diagnostic)≈17%2439–2441 munder overhead cover terrain reads 1065.5% at 3946–3948 m across a structure — excluded
3 m (diagnostic)≈16%2495–2498 munder overhead cover terrain reads 862.9% at 3946–3949 m across a structure — excluded
5 m≈16%2495–2500 munder overhead cover terrain reads 520.3% at 3944–3949 m across a structure — excluded
10 m≈15%2490–2500 munder overhead cover terrain reads 262.9% at 3939–3949 m across a structure — excluded
20 m≈14.8%2477–2497 munder overhead cover terrain reads 133.8% at 3929–3949 m across a structure — excluded
25 m≈14.8%2475–2500 munder overhead cover terrain reads 108.0% at 3924–3949 m across a structure — excluded
50 m≈14.1%2453–2503 munder overhead cover terrain reads 50.1% at 3914–3964 m across a structure — excluded
100 m≈13.7%2413–2513 munder overhead cover terrain reads 32.0% at 3849–3949 m across a structure — excluded

may start earliermay continue beyond end Extent detection suggests reviewing where this climb starts/ends.

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 ·

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

  © OpenStreetMap contributors · topo tiles © OpenTopoMap (CC-BY-SA) · vector tiles OpenFreeMap · aerial imagery © IGN, BD ORTHO® (Licence Ouverte Etalab 2.0)

Le Mauvais Pas from Pian del Colle 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).

Le Mauvais Pas from Pian del Colle elevation profile
Le Mauvais Pas from Pian del Colle rolling gradient profile
 

Measurement card

ElevationIGN 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 / CRS0.5 m grid, EPSG:2154; sampled every 1.0 m, bilinear interpolation
TilesE987-N6444, E987-N6445, E988-N6444, E988-N6445
Road centrelineOpenStreetMap (local PBF extract)
Quality statusevidence quality B; caveated windows: structure excluded
AnalysisOCL 0.1.0, analysis 0.1.0, run fr-alps4, calculated 2026-09-17

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:2154",
  "elevation_resolution_m": 0.5,
  "elevation_tiles": [
    "data/cache/fr/ign-lidarhd_dtm_E987-N6444_0m5.tif",
    "data/cache/fr/ign-lidarhd_dtm_E987-N6445_0m5.tif",
    "data/cache/fr/ign-lidarhd_dtm_E988-N6444_0m5.tif",
    "data/cache/fr/ign-lidarhd_dtm_E988-N6445_0m5.tif"
  ],
  "calculated_at": "2026-09-17T02:01:16+00:00",
  "road_source": "OpenStreetMap (local PBF extract)",
  "road_attribution": "\u00a9 OpenStreetMap contributors, ODbL",
  "osm_pbf_path": "data/cache/pbf/block-batch-fr-alps4.osm.pbf",
  "osm_snapshot": "",
  "run_id": "fr-alps4",
  "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": [
    "E987-N6444",
    "E987-N6445",
    "E988-N6444",
    "E988-N6445"
  ],
  "elevation_blocks": [
    "21LHD6QM@2025-02-20"
  ],
  "ign_dalles": [
    "LHD_FXX_0987_6445_MNT_O_0M50_LAMB93_IGN69",
    "LHD_FXX_0987_6446_MNT_O_0M50_LAMB93_IGN69",
    "LHD_FXX_0988_6445_MNT_O_0M50_LAMB93_IGN69",
    "LHD_FXX_0988_6446_MNT_O_0M50_LAMB93_IGN69"
  ],
  "ign_missions": [
    "21LHD6QM"
  ],
  "ign_editions": [
    "2025-02-20"
  ],
  "ign_dsm_edition": {
    "LHD_FXX_0987_6445_MNT_O_0M50_LAMB93_IGN69": "2025-02-20",
    "LHD_FXX_0987_6446_MNT_O_0M50_LAMB93_IGN69": "2025-02-20",
    "LHD_FXX_0988_6445_MNT_O_0M50_LAMB93_IGN69": "2025-02-20",
    "LHD_FXX_0988_6446_MNT_O_0M50_LAMB93_IGN69": "2025-02-20"
  },
  "climb_origin": "named-pass",
  "structure_own_ways": "none \u2014 the route carried no way list; own decks unmasked",
  "carriageway": {
    "stations": 174,
    "stations_resolved": 174,
    "width_median_m": 7.25,
    "width_p10_m": 5.25,
    "width_min_m": 0.5,
    "width_max_m": 11.75,
    "bounded_share": 0.42,
    "unbounded_share": 0.58,
    "confidence_median": 0.0,
    "width_median_bounded_m": 6.75,
    "window_m": [
      2475.0,
      2500.0
    ],
    "width_at_max25_m": 6.88,
    "window_stations": 6,
    "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": 174,
      "stations_resolved": 174,
      "width_median_m": 8.25,
      "width_p10_m": 5.83,
      "width_min_m": 1.0,
      "width_max_m": 12.0,
      "bounded_share": 0.661,
      "unbounded_share": 0.339,
      "confidence_median": 1.0,
      "width_median_bounded_m": 7.5,
      "window_m": [
        2475.0,
        2500.0
      ],
      "width_at_max25_m": 8.0,
      "window_stations": 6,
      "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"
}