Rue des Myrtilles
1594.0 m · net rise 192.2 m · total ascent 194.4 m · overall 12.1% · evidence quality B (good) · Le Chambon-Feugerolles · Loire · share
Shape: sustained — 27% of the climbing sits in a quarter of the distance; longest continuous stretch at 10%+ is 244 m.
Found purely from mapping and LiDAR data, and not yet matched against books, race records or lists — it may be well known to locals under a name we've never heard. It was cross-checked against IGN’s BD TOPO® road network, OpenStreetMap and the classified LiDAR HD point cloud, but a discovery can still be an artifact of the terrain model or the map. Treat it as a well-evidenced hypothesis until someone has ridden it. If you know this road, tell us what you found — photographs, corrections and local knowledge all welcome; the map links below let you scout it first.
Gradient ladder what do windows mean?
| Window | Maximum | Located at | |
|---|---|---|---|
| 2 m (diagnostic) | ≈26% | 1285–1287 m | under overhead cover terrain reads 414.9% at 23–25 m across a structure — excluded |
| 3 m (diagnostic) | ≈24% | 1284–1287 m | under overhead cover terrain reads 333.2% at 23–26 m across a structure — excluded |
| 5 m | ≈21% | 1282–1287 m | under overhead cover terrain reads 212.0% at 22–27 m across a structure — excluded |
| 10 m | ≈19% | 1583–1593 m | under overhead cover terrain reads 107.9% at 22–32 m across a structure — excluded |
| 20 m | ≈18.7% | 1285–1305 m | under overhead cover terrain reads 53.3% at 13–33 m across a structure — excluded |
| 25 m | ≈18.7% | 1283–1308 m | under overhead cover terrain reads 42.8% at 7–32 m across a structure — excluded |
| 50 m | ≈17.4% | 1543–1593 m | under overhead cover terrain reads 23.7% at 22–72 m across a structure — excluded |
| 100 m | ≈16.0% | 1280–1380 m | under overhead cover |
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 (0% unpaved), according to BD TOPO®, IGN's national topographic database: paved for the first 1,488 m; surface unrecorded from 1,488 m to the top.
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%
© OpenStreetMap contributors · topo tiles © OpenTopoMap (CC-BY-SA) · vector tiles OpenFreeMap · aerial imagery © IGN, BD ORTHO® (Licence Ouverte Etalab 2.0)
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 | E803-N6476, E803-N6477, E803-N6478, E804-N6477 |
| Road centreline | OpenStreetMap (local PBF extract) |
| Quality status | evidence quality B; caveated windows: canopy or structure, structure excluded, structure excluded min |
| Analysis | OCL 0.1.0, analysis 0.1.0, run fr-mc7, calculated 2026-09-22 |
Provenance
{
"analysis_version": "0.1.0",
"run_manifest": {
"manifest_version": "1",
"code_git_sha": "076a8e7f889cfb3c2cf6b3de65a6030c7155b1f0",
"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-mc7",
"road_pbf": "block-batch-fr-mc7.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_E803-N6476_0m5@22LHD5NM-2025-02-27.tif",
"data/cache/fr/ign-lidarhd_dtm_E803-N6477_0m5@22LHD5NM-2025-02-27.tif",
"data/cache/fr/ign-lidarhd_dtm_E803-N6478_0m5@22LHD5NM-2025-02-27.tif",
"data/cache/fr/ign-lidarhd_dtm_E804-N6477_0m5@22LHD5NM-2025-02-27.tif"
],
"calculated_at": "2026-09-22T14:43:19+00:00",
"road_source": "OpenStreetMap (local PBF extract)",
"road_attribution": "\u00a9 OpenStreetMap contributors, ODbL",
"osm_pbf_path": "data/cache/pbf/block-batch-fr-mc7.osm.pbf",
"osm_snapshot": "",
"run_id": "fr-mc7",
"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": [
"E803-N6476",
"E803-N6477",
"E803-N6478",
"E804-N6477"
],
"elevation_blocks": [
"22LHD5NM@2025-02-27"
],
"ign_dalles": [
"LHD_FXX_0803_6477_MNT_O_0M50_LAMB93_IGN69",
"LHD_FXX_0803_6478_MNT_O_0M50_LAMB93_IGN69",
"LHD_FXX_0803_6479_MNT_O_0M50_LAMB93_IGN69",
"LHD_FXX_0804_6478_MNT_O_0M50_LAMB93_IGN69"
],
"ign_missions": [
"22LHD5NM"
],
"ign_editions": [
"2025-02-27"
],
"ign_dsm_edition": {
"LHD_FXX_0803_6477_MNT_O_0M50_LAMB93_IGN69": "2025-02-27",
"LHD_FXX_0803_6478_MNT_O_0M50_LAMB93_IGN69": "2025-02-27",
"LHD_FXX_0803_6479_MNT_O_0M50_LAMB93_IGN69": "2025-02-27",
"LHD_FXX_0804_6478_MNT_O_0M50_LAMB93_IGN69": "2025-02-27"
},
"climb_origin": "discovered",
"structure_own_ways": 8,
"carriageway": {
"stations": 70,
"stations_resolved": 70,
"width_median_m": 6.75,
"width_p10_m": 3.5,
"width_min_m": 1.0,
"width_max_m": 12.0,
"bounded_share": 0.171,
"unbounded_share": 0.829,
"confidence_median": 0.0,
"width_median_bounded_m": 3.38,
"window_m": [
1283.0,
1308.0
],
"width_at_max25_m": 3.75,
"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": 70,
"stations_resolved": 70,
"width_median_m": 8.75,
"width_p10_m": 4.0,
"width_min_m": 0.5,
"width_max_m": 12.0,
"bounded_share": 0.471,
"unbounded_share": 0.529,
"confidence_median": 0.0,
"width_median_bounded_m": 6.5,
"window_m": [
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],
"width_at_max25_m": 2.5,
"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"
}