Strafe für sac_scale im Wandern Profil

[hungerburg]

Mehr eine Frage, denn ein issue: Warum werden nackte Pfade (ohne weitere Spezifikationen) bevorzugt, wenn unweit ein mit sac_scale markierter Wanderweg existiert?

Mal angenommen, ich plane eine Wanderung, ein Teilstück davon führt vom Rastlboden zur Bodensteinalm; Beispiel mit Wandern Beta erstellt, aber mit SAC2 Profil kommt nicht viel andres raus.

https://brouter.de/brouter-web/#map=16/47.2998/11.3909/osm-mapnik-german_style,route-quality&lonlats=11.389756,47.296098;11.387775,47.303291&profile=hiking-beta

Das führt die Skipiste gerade hinauf, über einen Trampelpfad, hier gehen einfach viele nach unten, nach oben kaum wer; Ich setze also einen Wegpunkt am Seilbahnsteig gleich rechts, den die Bahngesellschaft ausgeschildert hat. Die Höhenmeter werden schön gedehnt.

https://brouter.de/brouter-web/#map=16/47.2998/11.3909/osm-mapnik-german_style,route-quality&lonlats=11.389756,47.296098;11.387072,47.299664;11.387775,47.303291&profile=hiking-beta

Man sieht sehr gut in der Kostencodierung (Wandern Beta besser als SAC2), dass die Serpentinen nicht angelegt wurden, weil die Wegbauer nach Kilometern bezahlt werden. Find ich super.

Nun schieb ich den Wegpunkt noch weiter nach Osten auf den AV Weg, gut markiert und womöglich das schönere Wandererlebnis.

https://brouter.de/brouter-web/#map=16/47.2998/11.3909/osm-mapnik-german_style,route-quality&lonlats=11.389756,47.296098;11.3913,47.300668;11.387775,47.303291&profile=hiking-beta

Die Reisezeiten sehen gut aus, graphhopper Wandern veranschlagt 42min, was abwärts gehend, in umgekehter Richtung, zügig aber nicht laufen ist. Brouter unterscheidet auf- und abwärts. Find ich super.

Wie gesagt, bRouter wählt die Skipiste, den höchstwahrscheinlich anstrengendsten Weg (hinaufwärts).

[poutnikl]

Note that Hiking-beta, as one of user profiles included in Brouter package is very obsolete version of my hiking profiles, all based on the common profile template

Unfortunately, my active German is very bad and passive one is not much better.

---- Google translate EN -> DE ----

Beachten Sie, dass Hiking-Beta als eines der im Brouter-Paket enthaltenen Benutzerprofile eine sehr veraltete Version meiner Wanderprofile ist, die alle auf der gemeinsamen Profilvorlage basieren

Leider ist mein aktives Deutsch sehr schlecht und passives nicht viel besser.

[hungerburg]

This is more a question, than an issue: Why are naked paths (no further specifications) preferred, when there is a hiking trail with sac_scale applied close by?

For example, I plan a tour, a part of it goes from Rastlboden to Bodensteinalm; There is indeed not much different between Wandern Beta and SAC2.

Case 1 goes straight up the downhill piste; there is a trotten path there, many use it for descend, only super trail runners go up there to shave off some seconds. So I place a waypoint on the Seilbahnsteig, a little to the east. Ascent meters get stretched much more humanely.

Case 2 looked a little less red in the cost factor view, when I first collected the routes. It is an example that proves, way builders do not make serpentines, because they get paid by the length of the way.

Case 3 another bit to the east is the well marked AV (Alpine Club) trail. Perhaps the most joyful way to hike up there.

brouter chooses the most strenuous path. I suppose, because the piste is just a plain path. Why is there a penalty on sac_scale in hiking profile?

(edit spelling)

[poutnikl]

It is possible the steepness penalty is not optimally balanced with distance in this case, so distance may be penalised more.

As a workaround for now, in the newer SAC2 profile, localise code below and experiment with it.

assign   SAC_scale_limit          2 
......
assign   SAC_scale_preferred      1

Increasing preferred value will partially suppress lower or no SAC ratings.
Limit is intended for chosen experience or physical conditions.

---

You may also try to increase uphillcutoffvalue to more discriminate steep uphills
and/or eventually experiment with uphillcostvalue.

The former sets the threshold in % of climbing when penalisation starts.
The latter express multiplicator of altitude gain penalised as extra distance.

E.g. for the defaults below,
5 km of 5% steepness means (5%-3%)x5000m x 7 = 100m x 7 = 700m extra distance penalty.

assign   uphillcostvalue      7
assign   uphillcutoffvalue      3

`

---

You may also increase

assign hiking_routes_preference 0.20

to 0.5 - 1.0

It is the relative distance penalty for not being a marked path.

[poutnikl]

BTW, my experience is all may be case dependent.

The uphill trails are often more or less straight up, while downhill trails are often serpentines to save your knees, while straight down path would be erosive.

It depends on particular terrain and available options. The downhill ski areál scenario is kind of specific.

[hungerburg]

Hell poutnikl, I feel the same: "Short cuts (Abschneider) destroy the vegetation" a common sign here says, I can only add, they also destroy the knees, at least make them hurt; but enough people do not care. Also, quite a lot of those short cuts are mapped around here, it is not specific to skiing pistes. Will toy with params a little, though I think that should not be necessary: A bare path, not much can be said of it. While a mountain_hiking path, one knows a little bit.

[hungerburg]

Makes fun:

• path_preference: 10.0 no change, 15.0 will turn the AV trail orange, 20 turn it yellow, last two make it preferred;
• SAC_scale_preferred: 2 will keep the AV trail red, yet still make it preferred;

Looking at the data section: latter will tilt the balance more from km$ to ele$. So it is more about energy ;) Steepness above my level of understanding right now.

[poutnikl]

A kind of making fun is the philosophy of my biking and hiking profiles. Having a single, default, baseline profile aka a profile template, and then tuning, bending, tweaking and stretching it by changing its various parameters.

BTW, for discussion, feature requests or bug reports related to my profiles, it would be better go to my respective GitHub repositories, referred by the links above.

See also GitHub - poutnikl and GitHub profiles wiki

[hungerburg]

Well, then carry this over!