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How Finland's MTB trail map came to be: 12 years of active community mapping
An analysis of how OpenStreetMap mapping developed in Finland 2007–2025. Partly written by AI, checked and edited by a human.
Introduction
When you open the Trailmap app and see thousands of mountain bike trails all over Finland, you might wonder: where did all this come from? Who has mapped all these trails, marked their difficulty levels and added the details about surfaces and width?
The answer is both simple and astonishing: this is the work of the community. Of volunteer mappers who have, gradually, trail by trail, built a comprehensive map of Finland's mountain bike trails into the OpenStreetMap database.
But how did it actually happen? This piece is based on a thorough analysis of the change history of OpenStreetMap data relating to MTB-classified trails in Finland, and tells the story of how community mapping grew to its present scale over 12 active years (2013–2025).
The scale of the achievement
The length of MTB-classified trails in Finland: growth over the years
Let's start with the numbers that tell the story:
- 29029 kilometres of classified MTB trail (trails only)
- 166759 ways (OSM "way") of trail (path) and wider track mapped with an mtb:scale tag (139162 of them plain trail, i.e. path)
- 10324 ways of other types carrying an MTB classification (unclassified, cycleway, footway, service) — mtb:scale was originally intended only for highway=path trails, but it has been extended to other types of way as well, because it is useful for gravel riding, for instance, and there is no equally good alternative tag (e.g. mtb:scale=0- is a well-understood marker for a smooth, good-surfaced path)
- 12 years of active mapping work (2013–2025), after the pioneer phase
- 3056 mappers have taken part in mapping trails and other paths (those carrying an mtb:scale tag)
- 1178 mappers have actively added MTB-specific information (mtb:scale tags)
- 99.1 % of the mapped trails use valid mtb:scale values
MTB:scale distribution (trails only)
| mtb:scale | Trails | % | Kilometres |
|---|---|---|---|
| 1 | 61198 | 42,9% | 12735 km |
| 2 | 36963 | 26,0% | 7704 km |
| 0 | 23232 | 16,3% | 4589 km |
| 3 | 8328 | 5,8% | 1695 km |
| 0+ | 2370 | 1,7% | 522 km |
| 0- | 1768 | 1,2% | 465 km |
| 4 | 1526 | 1,0% | 307 km |
Difficulty 1 (a fairly easy "yellow" trail) is the most common at 42.9 %, but a significant share (26.0 %) is the more technical scale 2 class (orange). In total 85.2 % of all trails are in the 0-2 range (including 0+/0-).
But sheer quantity does not tell the whole story. What is more interesting is how this was achieved.
Three eras: From pioneers to the mainstream
New MTB-classified trails per year
The history of MTB mapping in Finland divides clearly into three phases:
1. The pioneer era (2007–2013): The foundation forms
The first years were quiet pioneer work. A small group of mappers laid the groundwork:
- Only a handful of active mappers each year
- On average fewer than 1000 new mtb:scale tags per year; mapping trails without MTB classification was relatively much more active
- But: persistence — 16 mappers have been active for over 10 years
OpenStreetMap ("OSM") was founded in the UK in 2004 and spread from there to other countries fairly quickly. In every country the starting point was a "blank map", i.e. absolutely all the map data had to be created from scratch. The work of these pioneers was central above all to developing the overall base of OSM data, and along the way some MTB-classified trails began to appear on the map too.
2. The growth period (2013–2019): Organised mapping
In 2013 came the first significant rise — annual new tags climbed above 2000. This corresponds to the period when Finnish mappers started to organise:
- The active mapping support and guidance that Antti Nissinen started in Tampere got going, and along with Antti a small group of activists began mapping trails in their local area
- The first MTB map style and map tile server resembling today's became available
- The number of active MTB mappers grew gradually and the number of MTB classifications per year multiplied
- Over the years the coverage of the MTB map spread beyond greater Tampere as a few other cities were supported too
- The Garmin MTB map in 2016 and the Bikemap app in 2018 strengthened both the mapping and the use of the map, which started to show in 2019
3. Mapping goes mainstream (2020–today): The breakthrough
2020 was the turning point. The numbers tell of a dramatic change:
| Metric | 2019 | 2020 | Change |
|---|---|---|---|
| New mtb:scale tags | 8672 | 32868 | +279 % |
| Active MTB mappers | 114 | 328 | +188 % |
| Top 200 active | 47 | 123 | +162 % |
What caused the 2020 explosion?
- The COVID-19 pandemic massively increased the popularity of outdoor and nature pursuits
- The Trailmap app released in 2020 made OSM data immediately useful and visible to end users
- A positive feedback loop: a better map → more users → more mappers → a better map
This was not a passing boom. Since 2020 mapping has settled at a sustainable level:
- 16000–22000 new tags per year (vs. 2500–8700 before 2020)
- 342–383 active MTB mappers per year
- Excellent commitment: 61.8 % of the mappers who started in 2020-2023 are still active
The number of active mappers per year
The number of active MTB mappers took a significant jump in 2020 and has stayed at a high level ever since.
Annual edits to MTB trails, including new trails
The number of edits grew in the same proportion as the number of active MTB mappers: mapping spread to many new cities and, for instance, in the Helsinki region it really got going for the first time. Once mapping started in trail-rich areas, results began to appear very fast.
An explanation for the success?
Finland's OSM trail mapping is quite exceptional even on a global scale: in Europe I know of only Italy being some 5000 km ahead of us, and the other countries are far behind, our Nordic neighbours included. Relative to population we are simply in a class of our own. What explains this exceptional performance?
My own assessment of the explanatory factors is as follows:
- Everyman's right and the extensive trail networks near population centres are probably the single most important factor: there are plenty of trails fit for MTB riding, they just have to be found
- The mapping Antti started in Tampere in 2013 put a strong platform in place: guidance, an MTB trail map that refreshed every night and a critical mass of mappers creating the data --> the MTB map quickly became useful for the sport and the mappers' work showed up immediately as a better map
- Thanks to Antti, OSM-based trail mapping had time to take root before some other approach could gain a foothold: in Sweden, for instance, Trailforks's closed platform gained a dominant position and OSM trail mapping has been left out in the cold; many other countries have their own local one-off apps that have at the very least slowed the spread of OSM mapping
- OSM mapping both is and is not "communal": the work mappers do together produces the result, but on the other hand cooperation and coordination between mappers is fairly minimal (OSM philosophy) — perhaps this way of working together suits the Finnish mindset well?
- Following on from that: the weak point in OSM's community structure is taking care of the tasks that make productive mapping and use of the map possible (a map app, guidance, a discussion forum, tools and so on) — in Finland, since Antti's start in 2013, there has always been at least 1 person putting significant time into supporting mapping and the use of the map
- A strong foundation built over 7 years met favourable conditions in 2020 and boom!
OSM mapping is done for many motives; mapping as a hobby and supporting open data as a principle are probably at least part of the motive for many mappers — possibly a very significant part, especially where the mapping work done is not all that easy to trace to a concrete benefit.
For trail mapping the situation appears to differ from the OSM mainstream. Based both on discussion and on observation, for a significant share of trail mappers the key motivation is their own direct benefit and the benefit that comes from the trail mapping community doing things together. They feel more of a connection to fellow riders, i.e. MTB enthusiasts, than to the wider OSM and open data communities. The benefit of the mapping is very concrete and immediate: you get information about the trails you need for MTB riding — information that is not really available from any other channel.
For those reasons I believe that discussing OSM trail mapping on MTB enthusiasts' forums, rather than on general OSM forums, and the roles of the MTB map and later the Bikemap & Trailmap app, have been critical to the success of OSM trail mapping.
A good comparison is what happened in Sweden, where OSM trail mapping got started around the same time as in Finland (MTB mapping was level until 2016) but never took off, once the Trailforks app and its closed mapping platform became popular among MTB enthusiasts. The rapid growth in Trailforks's users, and with them mappers, made it the dominant solution and pushed the competing options aside. Today Sweden has some 5000 km of MTB-classified trail in OSM, and only around 1000 km has been added in the last 5 years — while Trailforks reports some 42000 km of MTB-classified trail in Sweden.
The concentration paradox
The top mappers' share of all edits to MTB-classified trails
One of the most interesting findings of the data analysis is the extreme concentration of trail mapping:
- The top 33 mappers (1.6 % of mappers) have made 50 % of all MTB edits
- The top 160 mappers (7.6 % of mappers) → 80 % of all MTB edits
- The top 290 mappers (13.7 % of mappers) → 90 % of all MTB edits
The same pattern is found in many other successful open / crowdsourcing projects (Wikipedia, Linux).
Concentration is not a problem but a common phenomenon in open, crowdsourcing-based projects. It also shows in the fact that contributors (mappers) are a very small group (clearly under 1%) relative to the users of the map. Enough mappers are needed, but concentration has its advantages too:
- Consistency: Experienced mappers know the tagging standards and their example guides what all mappers do
- Coverage: Systematic work ensures regional coverage, and the so-called long tail of mapping then carries on from there
- Expertise: Those who have made thousands of edits have developed deep skill at mapping
The regional dimension
Mapping is not evenly distributed:
- The surroundings of the big city regions (Helsinki, Tampere, Turku, Oulu, Jyväskylä) are intensively mapped
- Top mappers often focus on their own home region, nearby areas and places they travel to on holiday
- More sparsely populated remote areas have fewer mappers, but also fewer trails
- Active areas have dozens of mappers overlapping, quieter areas a handful
This is a natural result of mappers finding and marking trails in their own riding areas. Often even a single very active mapper in a new area gets that area's mapping to a good level within a few years.
Endurance and commitment
The success of a community project depends on whether people stick around.
The commitment of the top mappers
A very significant share of the all-time top mappers are still active, even though community projects typically see significant natural churn as people's interests and available time change over the years.
- Top 10: 80 % still active (8/10)
- Top 20: 85 % still active (17/20)
- Top 100: 59 % still active (59/100)
- Top 200: 61.5 % still active (123/200)
Note: Top XX means the most active MTB mappers across all edits made between 2007 and 2025.
Time spent active
- Average time active: 6.4 years
- Median: 6.0 years
- Longest run: 18 years (since 2007)
- Active for over 10 years: 16 mappers
Continuity across eras (top 100)
| Era | Started | Still active | Continuity |
|---|---|---|---|
| pre-start (before 2013) | 11 | 7 | 63,6 % |
| Start (2013-2017) | 16 | 5 | 31,2 % |
| Bikemap (2018-2019) | 13 | 8 | 61,5 % |
| Trailmap (2020-2023) | 55 | 34 | 61,8 % |
| Trailmap v2 (2024-2025) | 5 | 5 | 100 % |
Other observations
The long tail (top 290-500)
The top 290 covers 90 % of the mapping. The next 200 mappers (top 290-500) represent an active middle tier — regular regional mapping without peak volume. This layer is important for regional coverage.
In addition, 243 low-contribution mappers (≤5 edits) and 1878 non-MTB mappers add details and make edits to geometry.
Seasonal variation
August has 5x more tags than February (19814 vs 4013). Winter mapping is nonetheless surprisingly significant: no good explanation for this has been found yet, though mtb:winter, i.e. the winter MTB classification, remains unexamined.
Data quality
- 99.1 % use valid mtb:scale values (only ~0.9 % invalid tags)
- 78.6 % of trails (path) were created with an mtb:scale tag right from version 1 — very high activity among MTB mappers, even though some new segments come from splitting existing trails
- 36 % of trails include a width tag — already quite good, although more would be welcome
- Edits: 52 % geometry, 48 % tags — continuous mapping of new things as well as improvement of what exists
- 21401 edits concern changes to the mtb:scale value (5 % of all edits) — significant, but not "edit wars"-type squabbling
Closing words
Thanks to all the mappers, both those active today and those who over the years have made the OSM database better. Together we have achieved a rather valuable result!
If some question about mapping and mappers is nagging at you, drop an email to markus at trailmap.fi.
This analysis is based on a comprehensive analysis of OpenStreetMap history in Finland, covering all mtb:scale-tagged trails from 2007–2025. In total 430672 version changes and 166759 individual trail/path segments were analysed in order to understand how Finland's MTB trail map came to be.
All usernames have been left out to protect privacy, even though OSM data is public.