How mapping is counted

What the Mapping board, the region pages and a profile's mapping table measure, where the numbers come from, and what they cannot see. Written Sept 27 2026 for the first linked mapper; kept true as the counter changes.

The unit is trail ways and trail miles, never changesets

A changeset is one edit session. Two mappers doing the same work can produce one changeset or eighty, so sessions are not the score. JuicyTrails counts which trail ways you touched and how many trail miles that was, per calendar year. Changesets are only the index we walk to find your edits.

What counts as a trail

A way whose highway tag is one of path, footway, cycleway, bridleway or track. That is the same list the track scorer uses to decide which ways a GPX track can claim. A road never counts, whatever else you did to it. Route relations are not counted (see the limits below).

Not highway=track: a dirt road can be driven, and the speed check only catches gross cheating. So the mapping counter's four trail classes — path, footway, cycleway, bridleway — leave track out, even though a track still counts toward a claim above. The Trail-miles board uses this same four-class definition to decide which miles of a track it counts.

Scope: anywhere, and independent of the challenge

• Anywhere in the world. Your global credit has no geographic boundary. A trail you fix in Colorado, Scotland or Patagonia counts the same. The rule behind it: mapping anywhere counts; nobody is excluded for where they map.
• Any trail edit, not only challenge work. An edit counts whether or not it came from a JuicyTrails track, sign photo or nomination. Fixing a trail you know from memory counts exactly like mapping a stretch someone recorded here. The link between the challenge and the edit is the person, not the edit.
• Regions are the only fence. A region page (Lower Loop, Snodgrass, …) shows the same numbers restricted to ways inside that region's bounding box. Your global total and a region's total are separate counts.
• Two ledgers, one board. Tracks and sign photos earn points; mapping earns mapping credit. They are shown side by side and never added together.

When credit starts

Credit begins at your count-from date, shown on your Me page next to the link. There is no backfill of past years: challenges are seasonal and everyone starts from where they link. Your all-time street cred on OpenStreetMap stays where it always was, on OpenStreetMap.

How the counter works, step by step

1. Find your edit sessions. From the public OpenStreetMap API the counter lists every changeset under your username between your count-from date and now. Linking through OpenStreetMap's own sign-in is what proves the username is yours; nobody can claim another mapper's work.
2. Read each session's actual edits. It downloads the change file of every changeset and looks at each way action: created, modified, deleted.
3. Decide whether the way is a trail, before and after the edit. For a modification it fetches the previous version to compare.
4. Classify.
   • created as a trail, or retagged from a non-trail into a trail → added
   • a trail before and a trail after (geometry or tags changed) → changed
   • deleted, or retagged out of the trail classes → removed
   • neither before nor after a trail → ignored
5. Measure. Each way's length is the great-circle distance along its nodes. Stored in kilometres, shown in miles.
6. Aggregate per calendar year. "Ways touched" is the number of distinct ways that year. A way you changed in ten separate sessions counts once; one big JOSM session that touches eighty ways counts eighty. This is the fairness rule: batching your work never costs you, and splitting it never pays.
7. Scope by region. The counter runs again per region with that region's bounding box and keeps only ways whose nodes fall inside.
8. Recompute nightly, from the start. Every night the counter reruns from your count-from date rather than adding to yesterday, so a correction to the rules corrects the history. OpenStreetMap's answers are cached forever because changesets never change, so reruns are cheap. A person is recounted at most once every 20 hours.

Where it shows, and the switch

Linking counts. Showing is your choice: the Show my mapping switch on your Me page (off by default) puts your numbers on the board's Mapping table for the season, on each region page you mapped in, and on your profile as a per-year table. Off means off at once; the numbers stay stored so switching back on is instant. Unlinking deletes them. The anonymous totals line under the board ("N mappers linked · N ways · N miles changed") counts every linked mapper, opted in or not, because it names nobody. JuicyTrails only reads OpenStreetMap; it never writes to it, and it never edits on your behalf.

What the counter cannot see (honest limits)

• Node drags. Moving a shared node in JOSM or iD without saving the parent way as its own element creates no new way version, so careful geometry work of that kind is undercounted today. Augmented diffs can close this for edits after about 2024; that is planned engine work.
• Historical lengths are approximate. Node positions are taken as they are today unless the same changeset moved them, so a way whose nodes moved later measures slightly off. Trail nodes rarely move far.
• Relations are ignored. A trail rerouted purely through a route relation, with no way edits, does not register.
• Quality is not measured. A revert or a bad edit counts like a good one. A steward's eye and the trail threads are the quality layer.
• Region scope is a box, not the polygon. An irregular region pulls in a little from just outside its outline until this is refined.