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Col du Mont Cenis from Moncenisio

Paved · ranked

12644.8 m · net rise 361.8 m · total ascent 499.8 m · overall 2.9% · evidence quality B (good) · Val-Cenis · Savoie

Shape: stepped — 48% of the climbing sits in a quarter of the distance; longest continuous stretch at 10%+ is 23 m.

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

Col du Mont Cenis from Moncenisio (Val-Cenis, Savoie) is 12644.8 m long at 2.9% overall; its steepest 25 m averages ≈10.1% and its steepest 100 m ≈8.6%, measured from IGN's LiDAR HD 0.5 m laser surveys along the mapped road centreline.

Gradient ladder what do windows mean?

Window	Maximum	Located at
2 m (diagnostic)	≈14%	785–787 m	under overhead cover terrain reads 692.8% at 941–943 m across a structure — excluded
3 m (diagnostic)	≈13%	784–787 m	under overhead cover terrain reads 469.0% at 940–943 m across a structure — excluded
5 m	≈12%	1847–1852 m	under overhead cover terrain reads 284.5% at 940–945 m across a structure — excluded
10 m	≈11%	1844–1854 m	under overhead cover terrain reads 145.7% at 940–950 m across a structure — excluded
20 m	≈10.4%	1834–1854 m	under overhead cover terrain reads 76.1% at 940–960 m across a structure — excluded
25 m	≈10.1%	1829–1854 m	under overhead cover terrain reads 62.3% at 940–965 m across a structure — excluded
50 m	≈9.4%	2034–2084 m	under overhead cover terrain reads 34.5% at 940–990 m across a structure — excluded
100 m	≈8.6%	1310–1410 m	under overhead cover terrain reads 20.3% at 940–1040 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%

Route line = the road surface as the LiDAR survey finds it. Basemap roads are for orientation and may sit a few metres off.

Col du Mont Cenis from Moncenisio 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	E1005-N6469, E1006-N6468, E1006-N6469, E1007-N6468, E1007-N6469, E1008-N6468, E1009-N6467, E1009-N6468, E1010-N6464, E1010-N6465, E1010-N6466, E1010-N6467, E1010-N6468, E1011-N6464, E1011-N6465, E1011-N6466
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 remeasure-260929c-fr, calculated 2026-09-29

Provenance

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  "calculated_at": "2026-09-29T16:13:27+00:00",
  "road_source": "OpenStreetMap (local PBF extract)",
  "road_attribution": "\u00a9 OpenStreetMap contributors, ODbL",
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    "LHD_FXX_1009_6468_MNT_O_0M50_LAMB93_IGN69": "2025-06-06",
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    "LHD_FXX_1010_6465_MNT_O_0M50_LAMB93_IGN69": "2025-06-06",
    "LHD_FXX_1010_6466_MNT_O_0M50_LAMB93_IGN69": "2025-06-06",
    "LHD_FXX_1010_6467_MNT_O_0M50_LAMB93_IGN69": "2025-06-06",
    "LHD_FXX_1010_6468_MNT_O_0M50_LAMB93_IGN69": "2025-06-06",
    "LHD_FXX_1010_6469_MNT_O_0M50_LAMB93_IGN69": "2025-06-06",
    "LHD_FXX_1011_6465_MNT_O_0M50_LAMB93_IGN69": "2025-06-06",
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  "structure_own_ways": 22,
  "structure_own_ways_source": "map-matched to the road network: the entry carried no way list, so the ways the route runs along were found by geometry (ukclimb.batch.own_ways_by_geometry)",
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    "max25_pct": 10.06
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