The series of maps below show how sport-recreational cycling in forest and nature reserve Den Treek has changed between 2016 and 2022. We mainly look at the use of forest paths by mountain bikers. The pdf of this story can be downloaded here:
To improve mountain biking, mountain bike route 'Den Treek' was officially opened in April 2020, together with mountain bike route 'Henschoten'. The realisation of the route was the result of years of discussions about facilitating or maintaining mountain biking in Den Treek. Before the construction, mountain biking on the estate had been done a lot 'randomly'. This led to friction with other users of the forest (hikers and horse riders), as well as natural damage (according to the AD in 2016: https://www.ad.nl/amersfoort/den-treek-handhaaft-verbod-mountainbikes-nu-wel-strikt~a04a8544/).
In this analysis, we look at the effect the construction of the new mountain bike routes has had on the use of this nature and recreation area as a whole. In doing so, we used data from Strava, the most widely used app by sporty cyclists in the Netherlands. About 40-60% of all Dutch cyclists use the app Strava to record cycling rides, some ~700,000 Dutch people in total. Mountain biking is included, but it is not exactly known how high the share of Strava users among mountain bikers is. Further research is being conducted on this.
TRACK-landscapes obtained access to Strava's data platform, Strava Metro, from Wielerplatform Utrecht, in consultation with the Province of Utrecht.
Through this platform -based on aggregated, anonymous data- images of path use can be made between 2016 and 2021. In this, the changes in path use of Den Treek, stood out strongly. On this, this additional analysis was made and compiled.
Meanwhile, track-landscapes has also started this type of research in other parts of the Netherlands (Gelderland, Overijssel and Limburg), in cooperation with NTFU.
Where did people cycle and mountain bike before the construction of MTB route Den Treek?
Images displayed below show route usage of Sporty/Recreational cyclists using the app Strava.
The 2016 and 2019 images are very identical, substantial differences/changes in route use are hardly visible, if at all.
In both 2016 and 2019 (and also in the years in between), several 'trails' were already being used by mountain bikers. Despite the fact that this was therefore not allowed. We know these are mountain bikers (and not road cyclists) because almost all of them are forest or dirt paths. These can only be ridden by bicycle on a mountain bike or gravel bike/cyclocrosser.
One clear through trail in particular is visible (colours Green and teal, indicated by circles). The route runs diagonally through the area from northeast to southwest, from the cycle viaduct at Nimmerdor past the Hazewater and the YMCA in a southwesterly direction along the new heathlands to the junction of the Doornseweg with the Zeisterweg. This was the route to the mtb route Zeist from Amersfoort, and was passed >2500 times a year (using Strava).
This stretch was well known to local mountain bikers as a fun route to go down on a mountain bike, despite not being allowed (Before 2016, people talked about the so-called 'tolerated trail').
And several of these 'unofficial' mountain bike trails also ran in the south-eastern corner of Den Treek. Actually, almost all of Den Treek-Henschoten's trails were used by mountain bikers.
Around pyramid Austerlitz, too, there was quite a bit of mountain biking. Here, too, several trails achieve more than 2,500 Strava passages per year.
As usage between 2016 and 2019 was almost identical, we take the 2019 image to compare with 2020, 2021 and 2022, during which the 'Den Treek-Henschoten' MTB routes were there. Mtb-routes Den Treek-Henschoten opened in April 2020, but was also unofficially usable from February 2020.
Between 2019 and 2020, major changes are visible as a result of the constructed mountain bike route.
Especially visible are the new mountain bike routes. In some places (for example: 1), it has been laid over the old 'tolerated trail'. Here, therefore, mountain bike use is increasing sharply (1).
But on the forest paths surrounding the mountain bike routes, a decrease is more likely to be seen. However, this decrease is not yet very large everywhere; there is still a lot of cycling on the forest trails; several forest trails still reach 500-1000 Strava passages per year. It is worth bearing in mind that the mountain bike route did not officially open until April 2020. This makes 2020 something of an 'in-between year'.
Other paved cycle paths were used significantly more intensively in 2020 compared to 2019. This is due to a sharp increase in the number of cyclists and mountain bikers, who also cycled more frequently. The use of Strava also increased significantly as a result (increase ~70% in Utrecht province).
Contrasts increase in 2021. The mountain bike route Den Treek-Henschoten, is used (with Strava) significantly more in 2021 than in 2020.
But the use of surrounding forest trails where cycling is not allowed, on the contrary, decreases even more. Most forest paths are now only passed 100-250 times in all of 2021. This sharp decline can be seen in several areas.
This does not continue in quite the same way in 2022 (January to July). The Den Treek mountain bike trail was used significantly less intensively. The corona periods will have caused extra crowding in 2021, but the drought in 2022 probably also plays a big role. Large parts of the MTB routes Den Treek-Henschoten were very poorly passable (very sandy) in spring and summer.
However; this did not lead to more cycling on the other forest trails; (improper) use seems to have decreased even more strongly here; in large parts of Den Treek, use has virtually disappeared.
Use of footpaths by sporty cyclists/mountain bikers
It is visually enlightening to filter this use by where cycling is and is not allowed. In the image below, all paths where cycling is allowed have been filtered out. What remains is the use of paths where cycling is not allowed.
However, this still contains an insurmountable accuracy error. If a footpath (where cycling is not allowed) is right next to a cycle path; GPS data is not accurate enough to always correctly determine whether someone was walking on the cycle or footpath. From a busy cycle path, some of the GPS tracks will be counted towards the footpath. This is the case in many of the path stretches that were widely used in 2022.
With a visual trick, this has been masked in the image below. All cycle paths and roads where cycling is allowed have been made 50 metres wide and put in the green background colour. Only the paths where cycling was truly improper remain in the image. The contrast between 2019 and 2022 is visibly very large.
In the Henschoten area, some trails still reach 100-250 passages. So that's five to ten Strava cyclists a week. This is also despite the increase in Gravelbikers, for whom these trails could still be interesting in their own right.
So since the construction of the Den Treek-Henschoten mountain bike trail, the unauthorised use of forest trails by Strava-using mountain bikers has virtually disappeared. And that is exactly what the co-intention of developing mountain bike trails is.
However, the question can still be asked whether any (changes in) enforcement of cycling off the beaten track has also had an impact on this inappropriate use of forest trails.
The question to what extent the Strava users are representative of the behaviour of all mountain bikers is also legitimate. It could be the case that non-Strava users cycle (relatively) more or less often outside the intended trails. New research is therefore being deployed on that question.
Even in the 'Hoge klei' area, use has disappeared, even though this is another area, where there is no mountain bike trail. It seems that the attraction of Den Treek, also causes a decline in mountain biking in other areas around the city of Amersfoort.