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Carr Road

1405.6 m · net rise 37.2 m · total ascent 73.4 m · overall 2.6% · evidence quality A (high) · North Union · Pennsylvania · share

Shape: sustained — 34% of the climbing sits in a quarter of the distance; longest continuous stretch at 10%+ is 135 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 state road inventory, OpenStreetMap and the point-cloud evidence for a graded road bed, 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: paved throughout, according to each state's road inventory.

Pending human review: the laser ground model dips and climbs back between 759 and 929 m, at or close to the steepest 25 m. That is the shape of a bridge the map does not show — or of a real hollow in the road. The figure is published as measured and has not been adjusted.

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 Aerial   © OpenStreetMap contributors · topo tiles © OpenTopoMap (CC-BY-SA) · vector tiles OpenFreeMap · aerial imagery USGS (public domain)

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

{
  "analysis_version": "0.1.0",
  "run_manifest": {
    "manifest_version": "1",
    "code_git_sha": "8f4becd2ed8ab26772f5cd961ca7d1d0c2823252",
    "code_git_dirty": "false",
    "analysis_version": "0.1.0",
    "analysis_config_digest": "sha256:8c94015b54267da4",
    "python": "3.14.4",
    "numpy": "2.5.3",
    "rasterio": "1.5.1",
    "pyproj": "3.8.0",
    "laspy": "2.7.0",
    "shapely": "2.1.2",
    "pyosmium": "4.3.1",
    "libosmium": "2.23.1",
    "gdal": "3.12.4",
    "proj": "9.8.1",
    "run_id": "remeasure-valley-260921-us",
    "road_pbf": "batch-usa-pa-west-chunk000.pbf",
    "region_key": "usa-pa-west",
    "crs": "EPSG:26917",
    "elevation_provider_key": "usa3dep",
    "authority": "usa-inventory",
    "registry_pbf": "pennsylvania-2026-09-07.osm.pbf",
    "tile_index_snapshot": "sha256:7efbee741b4e8cba"
  },
  "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:26917",
  "elevation_resolution_m": 1.0,
  "elevation_tiles": [
    "data/cache/usa/pa-west/USGS_1M_17_x61y443_PA_WesternPA_2019_D20.tif"
  ],
  "calculated_at": "2026-09-22T00:20:47+00:00",
  "road_source": "OpenStreetMap (local PBF extract)",
  "road_attribution": "\u00a9 OpenStreetMap contributors, ODbL",
  "osm_pbf_path": "output/valley-260921/us/batch-usa-pa-west-chunk000.pbf",
  "osm_snapshot": "",
  "run_id": "remeasure-valley-260921-us",
  "elevation_provider": "USGS 3DEP (The National Map)",
  "elevation_licence": "Public domain \u2014 USGS 3DEP 1 m DEM, courtesy of the U.S. Geological Survey",
  "elevation_dataset": "USGS 3DEP 1 m DEM, PA_WesternPA_2019_D20 (collected 2020)",
  "elevation_tile_ids": [
    "x61y443"
  ],
  "route_base_cut_m": 229.0,
  "climb_origin": "discovered",
  "canopy_check": "unavailable \u2014 EPT corridor failed: PA_WesternPA_2019_D20: HTTP Error 404: Not Found",
  "structure_own_ways": 2,
  "structure_own_ways_source": "map-matched to the road network: the entry carried no way list, so the ways the route runs along were found by geometry (ukclimb.batch.own_ways_by_geometry)",
  "prior_doc": {
    "slug": "carr-road",
    "calculated_at": "2026-09-07T23:05:26+00:00",
    "code_git_sha": null,
    "analysis_version": "0.1.0",
    "run_id": "pa-run4-260907",
    "path": "/root/uk-climbs/output/valley-260921/us/priors/carr-road/carr-road.json",
    "spans": 0,
    "sources": []
  },
  "carriageway": {
    "stations": 63,
    "stations_resolved": 63,
    "width_median_m": 7.25,
    "width_p10_m": 4.8,
    "width_min_m": 3.5,
    "width_max_m": 12.0,
    "bounded_share": 0.111,
    "unbounded_share": 0.889,
    "confidence_median": 0.0,
    "width_median_bounded_m": 5.25,
    "window_m": [
      689.0,
      714.0
    ],
    "width_at_max25_m": 6.25,
    "window_stations": 7,
    "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,
    "window_station_m": 5.0,
    "halfwidth_m": 6.0,
    "step_m": 0.25,
    "level_tol_m": 0.12,
    "break_min_m": 0.3,
    "stations_failed": 0,
    "hedge_to_hedge": {
      "status": "unavailable \u2014 no DSM raster (surface model absent or point-cloud only, which cannot serve off-line samples)"
    }
  },
  "unmapped_bridge_span": {
    "start_m": 530.0,
    "end_m": 700.0,
    "span_m": 170.0,
    "floor_at_m": 593.0,
    "depth_m": 10.6,
    "drop_m": 6.0,
    "surface": "raw",
    "window_start_m": 689.0,
    "window_end_m": 714.0,
    "gap_m": 0.0,
    "unstable": false,
    "perturbation_hits": 3,
    "note": "The ground falls 6 m below the road between 530 m and 700 m \u2014 11 m below the straight line joining the profile either side of it \u2014 and climbs back to that line, with the steepest 25 m at 689 m. That is a ravine under a deck OSM does not tag as a bridge, so no mask fired. Re-measure with mask_ranges_m over the span before this maximum stands (unmapped-bridge-span, Peter 2026-09-20)."
  },
  "remeasured": {
    "on": "2026-09-22",
    "why": "valley-crossing extent re-measure 2026-09-22: low-to-summit (229.0 m -> 1622.0 m)",
    "published_max25_pct": 20.57,
    "max25_pct": 20.56
  },
  "license": "ODbL-1.0",
  "license_url": "https://howsteep.org/licensing"
}