Discovered lane (51.1037, -3.6465)
536.8 m · net rise 57.9 m · total ascent 59.0 m · overall 10.8% · evidence quality A (high) · Withypool · Somerset · share
Shape: sustained — 37% of the climbing sits in a quarter of the distance; longest continuous stretch at 10%+ is 223 m.
Not yet matched against documented climbs — the measurement stands on its own.
Gradient ladder what do windows mean?
| Window | Maximum | Located at | |
|---|---|---|---|
| 2 m (diagnostic) | 38% | 22–24 m | |
| 3 m (diagnostic) | 36% | 21–24 m | |
| 5 m | 28% | 19–24 m | |
| 10 m | 23% | 171–181 m | |
| 20 m | 20.6% | 178–198 m | |
| 25 m | 21.0% | 173–198 m | |
| 50 m | 18.6% | 149–199 m | |
| 100 m | 16.9% | 99–199 m |
may start earlier 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
No aerial layer here: Britain has no open or government source of aerial photography at road scale — the pan-government APGB imagery is licensed to the public sector only, unlike the LiDAR this survey is measured from. Street View, where it exists, is the visual check.
This climb's data: OCL JSON — the full gradient ladder, quality flags and provenance in the OpenClimb Ladder format.
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%
© OpenStreetMap contributors · topo tiles © OpenTopoMap (CC-BY-SA) · vector tiles OpenFreeMap
Profile
The 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 | Environment Agency — EA LIDAR Composite DTM 1m (2022) |
|---|---|
| Resolution / CRS | 1.0 m grid, EPSG:27700; sampled every 1.0 m, bilinear interpolation |
| Tiles | SS8030.tif, SS8035.tif |
| Road centreline | OpenStreetMap (local PBF extract), snapshot 2026-08-12T20:21:46Z |
| Quality status | evidence quality A; no review flags; no caveated windows |
| Analysis | OCL 0.1.0, analysis 0.1.0, run chunk-02-260901, calculated 2026-09-01 |
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:27700",
"elevation_resolution_m": 1.0,
"elevation_tiles": [
"data/cache/england/bulk_dtm_1m/SS8030.tif",
"data/cache/england/bulk_dtm_1m/SS8035.tif"
],
"calculated_at": "2026-09-01T01:57:03+00:00",
"road_source": "OpenStreetMap (local PBF extract)",
"road_attribution": "\u00a9 OpenStreetMap contributors, ODbL",
"osm_pbf_path": "data/cache/pbf/england-2026-08-12-roads.osm.pbf",
"osm_snapshot": "2026-08-12T20:21:46Z",
"run_id": "chunk-02-260901",
"elevation_provider": "Environment Agency",
"elevation_dataset": "EA LIDAR Composite DTM 1m (2022)",
"elevation_licence": "Open Government Licence v3 \u2014 \u00a9 Environment Agency",
"elevation_coverage_id": "13787b9a-26a4-4775-8523-806d13af58fc__Lidar_Composite_Elevation_DTM_1m",
"elevation_tile_ids": [
"SS8030.tif",
"SS8035.tif"
],
"trimmed_from": "discovered-lane-51-1037-3-6465",
"trim_cut_m": [
[
0.0,
565.2
]
],
"license": "ODbL-1.0",
"license_url": "https://howsteep.org/licensing"
}