LIVING SURVEY — measurements are reviewed continuously as new data and local evidence arrive. Seen a sign, a gate, or a better name? Submit an updateno account needed · photos welcome via GitHub
Every climb on this site publishes its measurements as an
OCL document — a JSON format with one defining rule:
a maximum gradient cannot be expressed without its measurement
distance. The schema forbids windowless maxima. That is the whole
point: “32%” is unfalsifiable; “32% over 2 m, 27% over
25 m” is a measurement.
An OCL document carries the ladder (maxima over
explicit windows: 2 and 3 m diagnostic, 5–100 m standard), the
quality annotations you see on these pages (≈ canopy caveats,
excluded artifact zones with raw values preserved), an overall
evidence quality letter — what the figure rests on, not
how accurate it is
(A: fine source, clean standard windows · B: minor
interventions · C: coarser source or unresolved windows ·
D: coarse fallback · U: awaiting human review — rankings
default to A/B; what the letters
mean), external
claims kept strictly separate from measurements — each
with its evidence type and, where relevant, how the observation reached
us — and full provenance down to the LiDAR tile ids.
The spec and normative JSON Schema are public, versioned 0.1.0-draft
and open for comment:
specification ·
schema ·
comment.
Live documents: every climb page links its own OCL JSON (e.g.
cefn-llan.json), and each
survey's catalogue is summarized in a CSV:
UK, US, Switzerland, Austria and France. The decisions
dataset lists every route the survey ever considered — published, listed,
retired, or never given a page — with the coded reason.
One naming note for anyone reading the data: evidence quality is
carried in a field called confidence — in the OCL JSON, in
the confidence column of every catalogue CSV, and in the
spec. That name is fixed and will not change; only the words on these
pages did (19 September 2026).
Licence
The OCL specification text is CC BY 4.0 and the JSON Schema is MIT —
implement the format in anything, including closed commercial tools.
Datasets published in OCL carry their own licences in
provenance.license; this survey's documents are ODbL 1.0.
Full details for everything on this site:
licensing & reuse.