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Discovered lane (-41.6873, 173.1623)

603.6 m · net rise 45.3 m · total ascent 47.1 m · overall 7.5% · evidence quality A (high) · Marlborough · Marlborough · share

Shape: stepped — 56% of the climbing sits in a quarter of the distance; longest continuous stretch at 10%+ is 167 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 LINZ's Topo50 road centrelines, 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?

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: unpaved (82% unpaved), according to LINZ Topo50 road centrelines: paved for the first 108 m; unpaved from 108 m to the top. The steepest 25 m lies on the unpaved part.

Access: Listed 2026-09-28 (inventory hunt wave 1): road audit — way 1520335162: unnamed service way; barrier gate (no access tag) 0.0 m off route. Never silently ranked or dropped (Peter, 2026-08-27).

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

Load the interactive map

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

Topo (contours) Vector   © OpenStreetMap contributors · topo tiles © OpenTopoMap (CC-BY-SA) · vector tiles OpenFreeMap

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

Provenance

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  "run_manifest": {
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    "code_git_dirty": "false",
    "analysis_version": "0.1.0",
    "analysis_config_digest": "sha256:8c94015b54267da4",
    "python": "3.14.4",
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    "run_id": "nz-s3",
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    "crs": "EPSG:2193",
    "elevation_provider_key": "nz-linz",
    "tile_index": "stac",
    "authority": "linz",
    "registry_pbf": "new-zealand-2026-09-26.osm.pbf",
    "tile_index_snapshot": "sha256:65f98740b9968e3e"
  },
  "sample_interval_m": 1.0,
  "interpolation": "bilinear",
  "smoothing": "none",
  "gradient_windows_m": [
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  "diagnostic_windows_m": [
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  ],
  "elevation_crs": "EPSG:2193",
  "elevation_resolution_m": 1.0,
  "elevation_tiles": [
    "data/cache/nz/BR26.tiff"
  ],
  "calculated_at": "2026-09-28T05:07:08+00:00",
  "road_source": "OpenStreetMap (local PBF extract)",
  "road_attribution": "\u00a9 OpenStreetMap contributors, ODbL",
  "osm_pbf_path": "data/cache/pbf/block-batch-nz-s3.osm.pbf",
  "osm_snapshot": "",
  "run_id": "nz-s3",
  "elevation_provider": "LINZ nz-elevation",
  "elevation_licence": "CC BY 4.0 \u2014 Toit\u016b Te Whenua Land Information New Zealand \u2014 https://nz-elevation.s3.ap-southeast-2.amazonaws.com/LICENSE",
  "elevation_dataset": "New Zealand 1 m DEM/DSM national LiDAR mosaic \u2014 Toit\u016b Te Whenua Land Information New Zealand (LINZ), vertical datum NZVD2016 (LINZ documentation; not re-verified against a benchmark)",
  "elevation_tile_ids": [
    "BR26"
  ],
  "climb_origin": "discovered",
  "seam_filled_samples": {
    "count": 0,
    "distances_m": []
  },
  "seam_filled_in_maximum": false,
  "structure_own_ways": "none \u2014 the route carried no way list and no mapped way runs along it; own decks unmasked",
  "carriageway": {
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    "stations_resolved": 30,
    "width_median_m": 7.62,
    "width_p10_m": 4.25,
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    "window_m": [
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    "width_at_max25_m": 5.25,
    "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,
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      "bounded_share": 0.367,
      "unbounded_share": 0.633,
      "confidence_median": 0.0,
      "width_median_bounded_m": 7.25,
      "window_m": [
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      ],
      "width_at_max25_m": 9.75,
      "window_stations": 6,
      "status": "ok",
      "source": "dsm",
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      "halfwidth_m": 6.0,
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      "stations_failed": 0
    }
  },
  "license": "ODbL-1.0",
  "license_url": "https://howsteep.org/licensing"
}