7928.9 m · net rise 728.3 m · total ascent 734.8 m · overall 9.2% · evidence quality U (needs confirmation) · Flå · Buskerud
Shape: sustained — 32% of the climbing sits in a quarter of the distance; longest continuous stretch at 10%+ is 191 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 the NVDB road network, 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.
needs review short window divergence — treat short-window maxima here as provisional.
Gradient ladder what do windows mean?
| Window | Maximum | Located at | |
|---|---|---|---|
| 2 m (diagnostic) | ≈33% | 6571–6573 m | under overhead cover terrain reads 82.3% at 105–107 m across a structure — excluded |
| 3 m (diagnostic) | ≈32% | 6570–6573 m | under overhead cover terrain reads 74.9% at 104–107 m across a structure — excluded |
| 5 m | ≈28% | 6569–6574 m | under overhead cover terrain reads 54.0% at 102–107 m across a structure — excluded |
| 10 m | ≈20% | 6567–6577 m | under overhead cover terrain reads 27.8% at 102–112 m across a structure — excluded |
| 20 m | ≈16.5% | 618–638 m | under overhead cover terrain reads 20.3% at 6174–6194 m across a structure — excluded |
| 25 m | ≈15.9% | 3987–4012 m | under overhead cover terrain reads 19.0% at 6169–6194 m across a structure — excluded |
| 50 m | ≈14.9% | 4071–4121 m | under overhead cover terrain reads 16.0% at 6148–6198 m across a structure — excluded |
| 100 m | ≈14.5% | 4079–4179 m | under overhead cover |
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 (100% unpaved), according to NVDB, Norway's National Road Database: paved for the first 20 m; surface unrecorded for the first 80 m; unpaved from 80 m to the top. The steepest 25 m lies on the unpaved part.
Access: Listed 2026-10-05 (inventory hunt wave 1): road audit — way 713739114: service way, surface untagged; 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
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.
© 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
| Elevation | Kartverket NHM DTM 1 m (laser-covered ground only) — Nasjonal høydemodell (NHM) DTM, 1 m, EPSG:25833, NN2000 (Kartverket), served by the hoydedata.no ImageServer; ground without a laser project is a coarser resampled product and is never measured |
|---|---|
| Resolution / CRS | 1.0 m grid, EPSG:25833; sampled every 1.0 m, bilinear interpolation |
| Tiles | E189000-N6706500, E189000-N6707000, E189500-N6706500, E189500-N6707000, E189500-N6707500, E190000-N6706500, E190000-N6707000, E190000-N6707500, E190500-N6707000, E190500-N6707500, E190500-N6708000, E191000-N6707500, E191000-N6708000, E191000-N6708500, E191000-N6709000, E191000-N6710000, E191000-N6710500, E191000-N6711000, E191000-N6711500, E191500-N6707500, E191500-N6708000, E191500-N6708500, E191500-N6709000, E191500-N6709500, E191500-N6710000, E191500-N6710500, E191500-N6711000, E191500-N6711500, E192000-N6709000, E192000-N6709500, E192000-N6710000, E192000-N6710500 |
| Road centreline | OpenStreetMap (local PBF extract) |
| Quality status | evidence quality U; review flags: short window divergence |
| Analysis | OCL 0.1.0, analysis 0.1.0, run no-b05, calculated 2026-10-04 |
Provenance
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"region_key": "norway",
"crs": "EPSG:25833",
"elevation_provider_key": "nhm-no",
"tile_index": "nhm-window",
"authority": "nvdb",
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"sample_interval_m": 1.0,
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"scale_correction": "point",
"scale_correction_crs": "EPSG:25833",
"elevation_crs": "EPSG:25833",
"elevation_resolution_m": 1.0,
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"data/cache/no/nhm-no_dtm_E192000-N6709000_1m.tif",
"data/cache/no/nhm-no_dtm_E192000-N6709500_1m.tif",
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],
"calculated_at": "2026-10-04T03:57:07+00:00",
"road_source": "OpenStreetMap (local PBF extract)",
"road_attribution": "\u00a9 OpenStreetMap contributors, ODbL",
"osm_pbf_path": "data/cache/pbf/no-b05-block-batch-no-b05.osm.pbf",
"osm_snapshot": "",
"run_id": "no-b05",
"elevation_provider": "Kartverket NHM DTM 1 m (laser-covered ground only)",
"elevation_licence": "CC BY 4.0 \u2014 \u00a9 Kartverket (https://www.kartverket.no/api-og-data/vilkar-for-bruk)",
"elevation_dataset": "Nasjonal h\u00f8ydemodell (NHM) DTM, 1 m, EPSG:25833, NN2000 (Kartverket), served by the hoydedata.no ImageServer; ground without a laser project is a coarser resampled product and is never measured",
"elevation_vertical_datum": "NN2000",
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"elevation_blocks": [
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"nhm_laser_projects": [
{
"last_flight_date": "2008-01-01",
"name": "Fl\u00e5 Nes 2008",
"points_per_m2": 2,
"resolution_m": 0.5,
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{
"last_flight_date": "2024-09-19",
"name": "Hallingdal 5pkt del2 2024",
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},
{
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}
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"nhm_flight_season_unknown": [
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],
"nhm_retrieved_at": "2026-10-03T17:46:07Z",
"nhm_note": "laser projects overlapping the route's cells; the mosaic draws on them by its own priority and which project supplied which pixel is not recorded",
"climb_origin": "discovered",
"seam_filled_samples": {
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"distances_m": []
},
"seam_filled_in_maximum": false,
"structure_own_ways": 2,
"tunnel_check": "osm tunnel=* ways on 2 own way(s)",
"tunnel_ranges_m": [],
"underground_fraction": 0.0,
"carriageway": {
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"stations_resolved": 324,
"width_median_m": 4.38,
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"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",
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}
},
"license": "ODbL-1.0",
"license_url": "https://howsteep.org/licensing"
}