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

Via ai Monti

3660.6 m · net rise 404.3 m · total ascent 406.7 m · overall 11.0% · evidence quality B (good) · Ronco sopra Ascona · Ticino ·

Shape: sustained — 28% of the climbing sits in a quarter of the distance; longest continuous stretch at 10%+ is 735 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 swisstopo’s swissTLM3D road model, OpenStreetMap and a second terrain model, 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?

WindowMaximumLocated at
2 m (diagnostic)≈24%766–768 munder overhead cover terrain reads 134.9% at 3444–3446 m across a structure — excluded
3 m (diagnostic)≈22%766–769 munder overhead cover terrain reads 104.1% at 3444–3447 m across a structure — excluded
5 m≈20%765–770 munder overhead cover terrain reads 71.5% at 3442–3447 m across a structure — excluded
10 m≈18%762–772 munder overhead cover terrain reads 40.8% at 3442–3452 m across a structure — excluded
20 m≈17.0%825–845 munder overhead cover terrain reads 25.1% at 3442–3462 m across a structure — excluded
25 m≈16.8%820–845 munder overhead cover terrain reads 22.1% at 3442–3467 m across a structure — excluded
50 m≈15.9%795–845 munder overhead cover terrain reads 16.6% at 3442–3492 m across a structure — excluded
100 m15.7%751–851 m

may 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 swisstopo's swissTLM3D road model.

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 © swisstopo

Via ai Monti 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).

Via ai Monti elevation profile
Via ai Monti rolling gradient profile
 

Measurement card

Elevationswisstopo swissALTI3D — swissALTI3D 0.5 m DTM (Federal Office of Topography swisstopo)
Resolution / CRS0.5 m grid, EPSG:2056; sampled every 1.0 m, bilinear interpolation
Tiles2699-1111, 2699-1112, 2700-1111, 2700-1112
Road centrelineOpenStreetMap (local PBF extract)
Quality statusevidence quality B; caveated windows: structure excluded
AnalysisOCL 0.1.0, analysis 0.1.0, run ch-run7-260911, calculated 2026-09-11

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:2056",
  "elevation_resolution_m": 0.5,
  "elevation_tiles": [
    "data/cache/ch/swissalti3d_2022_2699-1111_0.5_2056_5728.tif",
    "data/cache/ch/swissalti3d_2022_2699-1112_0.5_2056_5728.tif",
    "data/cache/ch/swissalti3d_2022_2700-1111_0.5_2056_5728.tif",
    "data/cache/ch/swissalti3d_2022_2700-1112_0.5_2056_5728.tif"
  ],
  "calculated_at": "2026-09-11T03:22:38+00:00",
  "road_source": "OpenStreetMap (local PBF extract)",
  "road_attribution": "\u00a9 OpenStreetMap contributors, ODbL",
  "osm_pbf_path": "data/cache/pbf/switzerland-2026-09-10-batch.osm.pbf",
  "osm_snapshot": "",
  "run_id": "ch-run7-260911",
  "elevation_provider": "swisstopo swissALTI3D",
  "elevation_licence": "swisstopo open government data (OGD): free use, attribution '\u00a9 swisstopo' \u2014 https://www.swisstopo.admin.ch/en/terms-and-conditions",
  "elevation_dataset": "swissALTI3D 0.5 m DTM (Federal Office of Topography swisstopo)",
  "elevation_tile_ids": [
    "2699-1111",
    "2699-1112",
    "2700-1111",
    "2700-1112"
  ],
  "climb_origin": "discovered",
  "canopy_check": "unavailable \u2014 no surface model (DSM or point cloud) registered for this coverage",
  "mask_basin_extension_m": 29.0,
  "license": "ODbL-1.0",
  "license_url": "https://howsteep.org/licensing"
}