How to tag unknown activity scale like mtb:scale

julcnx · 2022-11-09T02:48:25.870Z

I have a use case where I am aware some specific trails are regularly used by MTBs but I do not know the exact activity scale

I am building a custom OsmAnd renderer and it would be nice to highlight those regular trails so that users/mappers fill in later the exact value.

Thinking about mtb:scale=yes or mtb:scale=unknown or mtb:scale=-1 which have been used a few times so far. (see taginfo)

Why just not avoid the tag completely? So we can differentiate them from other trails where we have no knowledge.

Another important aspect is some mappers have used for this purpose other tags like mtb=yes/no or bicycle=yes/no which were meant for signposted/legal access tags.

This makes it confusing for new mappers who may not be aware of the mtb:scale tag, and others may become lazy picking a scale value and just go for a simple yes/no access tag.

Ideally, I would like to do some cleanup in my area and convert existing bicycle=yes attached to mountain trails to a given mtb:scale value.

Mateusz_Konieczny · 2022-11-09T08:00:44.120Z

julcnx:

Why just not avoid the tag completely? So we can differentiate them from other trails where we have no/limited knowledge.

but if there is limited knowledge on both, then what is the point of differentiating them?

Nadjita · 2022-11-09T08:35:22.543Z

julcnx:

I am building a custom OsmAnd renderer and it would be nice to highlight those regular trails so that users/mappers fill in later the exact value.

Why not use a note then? If I have no clue how to map it properly, I prefer notes to “rough guessing” and maybe doing something wrong unintentionally

julcnx · 2022-11-09T08:54:06.819Z

Mateusz_Konieczny:

but if there is limited knowledge on both, then what is the point of differentiating them?

There is a difference between no and limited knowledge

Also legal access tags like bicycle=yes are often wrongfully used for this purpose, and so having an official mtb:scale=unknown would prevent this issue.

Nadjita:

Why not use a note then? If I have no clue how to map it properly, I prefer notes to “rough guessing” and maybe doing something wrong unintentionally

Because a note is free-text so it can’t be programmatically translated into a known condition like an official key/value combination.

Mateusz_Konieczny · 2022-11-09T08:56:08.632Z

julcnx:

There is a difference between no and limited knowledge

but what info mtb:scale=unknown gives?

Are you looking for “this is mtb route”? But note that mtb:scale can be also used not only on MTB tracks.

julcnx:

Because a note is free-text so it can’t be programmatically translated into a known condition like an official key/value combination.

fixme:mtb_route_data_missing=yes ?

julcnx · 2022-11-09T09:10:30.800Z

Mateusz_Konieczny:

but what info mtb:scale=unknown gives?

It would tell me that this trail can be done on a MTB, and it would give mappers (including me) and end-users (if supported by a renderer) an incentive to try it so it can be rated.

In my area, the majority of trails do not have scale information because most mountain trails are too dangerous/remote, so any information is valuable.

Mateusz_Konieczny:

fixme:mtb_route_data_missing=yes ?

Yes, something around this line would work but I wanted to check if there was a possibility to make anything official, because it’s not guaranteed that OsmAnd will accept some undocumented custom fixme tag to be integrated into their country dataset.

H · 2022-11-09T14:23:42.970Z

I’d use mtb=yes or even mtb=designated for this.

I know it’s supposed to be about legal access and not passibility, but in this case, it seems logical, and most uses of this key must mean more or less that, as described in the wiki.

From the discussion page:

So the only reason for mtb=designated would be that someone does not know the mtb:scale value - and therefore uses mtb=designated. In that case I agree it’s useful, […]

julcnx · 2022-11-09T14:43:12.709Z

H:

I know it’s supposed to be about legal access and not passibility, but in this case, it seems logical, and most uses of this key must mean more or less that, as described in the wiki.

Wouldn’t it be more logical if there was a documented mtb:scale=yes or mtb:scale=unknown ?

Mappers use mtb=yes and bicycle=yes because there is nothing else available for their purpose. Sometimes it’s laziness but most of the time people simply don’t remember or know the exact scale (when someone else gives you their GPS trace)

I do not want to use legal access tags because once you use them there is no way to distinguish them from ways that are actually signposted.

H · 2022-11-09T15:45:22.564Z

julcnx:

Wouldn’t it be more logical if there was a documented mtb:scale=yes or mtb:scale=unknown ?

For me, not really. mtb:scale=yes means nothing to me.

Maybe mtb:scale=unknown is not so bad, but it’s not that clear what the meaning would be.

In taginfo I also see mtb:scale=fixme (with the same number of use) which sounds more logical to me. Means that someone has to go and check…

julcnx · 2022-11-10T03:25:14.336Z

H:

In taginfo I also see mtb:scale=fixme (with the same number of use) which sounds more logical to me.

I like it! It clearly conveys that the mtb:scale must be filled in with a precise value, and if renderers support this in the future, it would give an incentive to end-users to contribute.

It’s a lot more logical than using another key (mtb, bicycle) that is meant for some other purposes (legal access tags).

Something like fixme:mtb:scale=yes similar to what Mateus proposed is another option but I fear it can have limitations:

renderers may not want to render extra special tags
it’s hard to read (long) and easy to make a typo
a mapper might miss it or ignore it in the list of available tags attached to a specific path

Does anyone have a better idea?