{
  "name": "Col du Grand Colombier",
  "slug": "col-du-grand-colombier",
  "url": "https://www.bestdrivingroads.com/roads/col-du-grand-colombier/",
  "summary": "The Jura's fiercest climb, cliff-cut lacets from Culoz to 1,501 m.",
  "roadNumbers": [
    "D120"
  ],
  "location": {
    "country": "France",
    "region": "Bugey, Ain",
    "start": {
      "name": "Culoz",
      "lat": 45.847918,
      "lon": 5.783099
    },
    "end": {
      "name": "Lochieu",
      "lat": 45.928796,
      "lon": 5.729057
    }
  },
  "measurements": {
    "lengthMiles": 18.1,
    "lengthKm": 29.1,
    "driveMinutes": 45,
    "corners": 35,
    "hairpins": 7,
    "maxGradientPercent": 14,
    "summitMetres": 1502,
    "difficulty": "demanding",
    "tightnessOutOf10": 7
  },
  "timing": {
    "bestSeasons": [
      "summer",
      "autumn"
    ]
  },
  "conditions": {},
  "hazards": [
    "Closed in winter, generally November until late April",
    "Ramps of 12 to 14 per cent on the Culoz hairpins",
    "Narrow cliff-cut lacets unsuitable for large motorhomes",
    "Heavy cyclist traffic in season"
  ],
  "scenery": [
    "mountain",
    "lakes"
  ],
  "pointsOfInterest": [
    "Fenestrez viewpoint",
    "Col du Grand Colombier summit",
    "Croix du Grand Colombier orientation table"
  ],
  "geometry": {
    "gpx": "https://www.bestdrivingroads.com/roads/col-du-grand-colombier/route.gpx",
    "pointCount": 270
  },
  "attribution": {
    "source": "Routes - bestdrivingroads.com",
    "citation": "Cite with a link to the road page. Stats are measured from the mapped line, not copied from other lists.",
    "roadGeometry": "(c) OpenStreetMap contributors, ODbL",
    "terms": "Facts are free to cite with attribution; bulk reproduction of the catalogue requires permission (simon@keane.studio)."
  },
  "updated": "2026-07-12"
}