First time writing a diary, I have no idea how this is supposed to work
First off I´m gonna talk about the class:bicycle tag
This tag is used to describe how comfortable a certain way is for a cyclist (with class:bicycle=3 being great and …=-3 being really bad). The tag is mostly subjective and surveys are needed.
I first started using it when OSM based routers kept routing me over a secondary road where it is technically legal (?) to cycle on but rather dangerous due to heavy motor traffic combined with a speed limit of 80km/h. Since only GraphHopper seems to be using the class:bicycle tag for it´s routing it´s the only OSM router which has now stopped telling me to use that road. Great success!
Now fast forward a few weeks and I found out that this tag is extensively used in Munich to “improve” bicycle routing. I don´t fully agree with the way the people there implemeted it as now busy roads are tagged as “better” as seperate cycleways due to irrelevant things such as width.
But I don´t live in Munich so it´s not my problem, so I´d rather focus on implementing this tag in the city of Unterschleißheim. I´ve already done some progress and pretty much every road and path in Lohof-Süd is now equipped with this tag to improve routing, and it did work pretty well as Graph Hopper uses the safer roads even if the route will end up being a few meters longer. Great success again!
I want to implement this tag in other areas of Unterschleißheim but I am not really sure how to make sure that I´ve reviewed every road. I thought about creating a spreadsheet with every road name of the city but that would take a lot of time or good overpass-api skills (which I don´t have). I´ve decided that I would split the city into different sectors and add the class:bicycle tag for those sectors one by one.
About mapillary…
While this doesn´t fit to the rest of the diary I still want to include this as it would help implementing the tag.
I´ve decided that I wanted to add mapillary coverage of Unterschleißheim using my phone attached to my bicycle. After finally figuring out how the mobile app works (thanks to some folks in the OSM-World Discord server) I tried attaching my phone to my bicycle using duct tape. Not professional but if it works why not? I spent about one and a half hours trying to duct tape my phone onto the headlight, making sure that nothing was in the way of the camera but I gave up realizing that I would just look like an idiot cycling around with a phone duct-taped to my bicycle headlight. So that means no mapillary imagery for my city until I´ve figured out a way
Discussion
Comment from map per on 21 May 2024 at 10:27
What’s interesting to know about class:bicycle in Munich is, that it’s basically an undocumented import by MunichWays (a division of the Green City association). I’m also not happy with every single road classification and the addition to OSM was a bit chaotic due to some beginners mistakes, people sometimes not responding to changeset comments and sometimes importing outdated data.
But on the other hand, MunichWays did a lot of detail work for classifying roads in Munich and the data is way easier to access for data consumers, now that it was added to the OSM database.
Comment from Richard on 23 May 2024 at 07:32
That’s because it’s a terrible subjective tag and shouldn’t be used. Much better to tag objective speed limits and traffic levels.
Comment from cyton on 26 May 2024 at 16:37
Oh, don’t be afraid to look like a doofus.
https://www.openstreetmap.org/user/cyton/diary/396135
Though i have since made the phone loose it’s ability to auto focus, because I’ve used it so much.
Then i bought a gopro max 360⁰, which i attached to the helmet on the top.
Those images are far superior to anyrhing else.
And it doesn’t look even remotely as silly.
Comment from Thomas-Munichways on 26 May 2024 at 16:50
We believe class:bicycle is invitable to get good routing results. Exaclty as you described your expiences in Unterschleißheim. Importent is a standardized or well described rating approach and a clear focus on the main target group, which are the less expierinced all day cylists. For other groups there are plenty of spezcial subtags. See https://www.munichways.de/berwertungskriterien-radwege/. There you can see that is not mainly about width. We first rated the main routes from north to south, east to west, etc. across the whole City, fococing on the very Bad and good ways. This alreafy improved quote a lot. Then we went departement by departement to complete.
Comment from Zverik on 26 May 2024 at 17:00
This really feels like surface:grade tag, which ranks the subjective quality of a road on a 0..3 scale :)
Comment from Coehill on 27 May 2024 at 12:06
Check out Panoramax as an alternative to the Facebook-owned Mapillary. Panoramax is truly open source, federated, and the devs are friendly and open to discussion.
Comment from Jarek 🚲 on 27 May 2024 at 13:38
A35K:
But this illustrates the problem with subjective tags like class:bicycle. Everyone will have a different idea of what a “better” roadway is.
Further, standards will vary between regions (e.g. what’s considered a good cycleway in Bavaria will probably be different from what’s a good cycleway in the Netherlands). So the only way to use class:bicycle extensively is to have a locally-agreed and well-documented guideline as to what the different classes are. But that will likely describe things like speed limit, presence of cycleways, incline, access control, or other objective characteristics that could be tagged instead.
It seems to me that the main remaining use of a class:bicycle tag would be to discourage routing bicycles over streets or roads that are bad for cycling for reasons difficult to describe with data. For example if a residential street is illegally but frequently used as a cut-through by car drivers, but accurate traffic level data is not available. Or if the legal speed limit and actual vehicle speeds are very notably different.
Richard:
I generally agree with this view, but given that accurate data on traffic levels is largely not available under a free licence, it’s a bit of a moot point and doesn’t address real pain points that people have.
However in this case it seems like avoiding roads with a 80 km/h speed limit and no cycleway would have handled the problem without needing a class:bicycle tag?
(That being said - I really like cycle.travel’s routing, it usually manages to find the best out of my region’s bad cycle infra - thanks Richard!)
Comment from AlaskaDave on 27 May 2024 at 13:40
I’ve been using these tags in Chiang Mai Province in Thailand for a number of years. Yes, they are subjective but I believe they can be useful to bicyclists. I make my own Garmin-compatible maps but haven’t yet figured out a way to make my Garmin unit understand them or use them for routing purposes so the info here regarding GraphHopper is helpful.
I don’t believe there is any way to define these tags more rigorously. Just as with the various schemes to quantify “drivability” of a highway, or even “smoothness”, it will always be a subjective rating based on users’ perceptions.
For example, my definition of a class 3 bicycle highway in the area where I ride in Thailand (smooth road, no traffic, scenic) might be vastly different from that of a bicyclist in Montana, or Italy.
Comment from Richard on 27 May 2024 at 14:11
Lots of administrations do release traffic data under an open licence - you’d be surprised!
But it’s something that we could and should survey for OSM. Broad-brush AADT equivalents (Average Annual Daily Traffic) are actually pretty easy to survey - the cut-off for safe cycling is often ~1000 cars per day, and you can extrapolate that pretty easily on many quiet roads.
Comment from Mateusz Konieczny on 31 May 2024 at 08:46
It is actually worse. People will disagree heavily in many cases and different cyclists have a better criteria. It is far better to tag objective info rather than trying to cram all criteria into single poorly defined tag.
Any use of class:bicycle tag should think hard “is it possible to express it properly”.
Comment from Mateusz Konieczny on 31 May 2024 at 08:46
Congrats, it worked well!
Comment from Jarek 🚲 on 31 May 2024 at 14:40
I’m kind of interested. I looked through the OSM wiki for AADT and volume but couldn’t find anything in a casual search… Is there any existing AADT or related tagging or OSM guidelines or information on how to survey it?
Comment from Datico on 2 June 2024 at 10:55
It would be interestung to set up a cheap esp32 module or something as a tracker to see how many cars pass a road in like a full week and then calculate an estimate AADT but I don’t know if that’d be too overkill
Comment from VileGecko on 11 June 2024 at 21:27
This is my first time encountering this tag but from what I get from the wiki page this is arguably one of the most subjective tags I’ve seen. It seems to pretty much disregard regional differences, cyclist’s experience and the median level of comfort in a given settlement. I live is a small city with nonexistent bike infrastructure - what is provided as an example of class:bicycle=-1 looks better than anything you’d find here. While this may sound bad at first I’d still be comfortable and safe enough to get distracted from the road for a bit and allow myself to fiddle with the phone attached to the handlebar (e.g. to check the map, skip a song in Spotify etc.). What I’d describe as “avoid at all costs” is the highway outside of the city with cargo truck traffic and the speed limit of 90 km/h (+20 km/h oopsie allowance). So, should we just give up any attempts to make those numbers mean anything universal and just assign “class:bicycle=-3” to a “literal fury road” and “class:bicycle=+3” to “as good as it gets”? If so, where exactly should the border be drawn with a la la land where “class:bicycle=-3” means “I’m slightly inconvenienced” and “class:bicycle=+3” stands for “all cyclists go to heaven”?
Comment from aseidel on 9 July 2024 at 15:16
Happy to see, there are more mappers using this tag! Thanks for your blog post - it reminds me to really take the plunge soon and write about our project’s experiences with this tag… :-) Feel free to take a look at our project Lüneburg Maps’ (#lgmaps) organised editing website on this tag: https://wiki.openstreetmap.org/wiki/Organised_Editing/Activities/LGMaps/class:bicycle (main project site: https://wiki.openstreetmap.org/wiki/Organised_Editing/Activities/LGMaps, still only in German, sorry to all the others). We have been (and still are) thoroughly using and testing this tag since 2019 around the city of Lüneburg (50 km south of Hamburg) and tried to implement a more systematic framework for assessing the bicycle-related subjective quality of road infrastructure. So far there are more than 2600 km road network around Lüneburg tagged width class:bicycle=. We are using this tag *in addition to the more objective tags like highway=, surface=, smoothness=* etc., not instead of them. We also have been using Mapillary since 2021 (yes, Panoramax would have been nicer), see https://www.mapillary.com/app/org/lgmaps. Mappers using the app instead of our 360° project-gopro just take sequences of photos along the way (like here: https://www.mapillary.com/app/?pKey=507597247397942), but some also applied the phone with duct tape to their bikes or helmets. No worries about looking weird… People will get used to you riding around like that :-D Anyway: thanks again for sharing your experiences! Please update us on how you get along with this tag. Cheers Antje