One use case for mapping is to record the number of toilets in a given area.
I searched for examples of tags used by other mappers and found that there are multiple ways to represent the same thing.
For example, I found at least two ways to represent “number of men’s seated toilets.”
I’d like to choose the best way to make the data easier to use mechanically. Which combination do you think is best?
One solution would be to create separate nodes for the men’s and women’s restrooms.
However, there would still be differences in “number” and “capacity,” and multiple combinations of key order would be possible.
A good way to proceed is to look at the usage numbers of tags with less components, e.g.
There is the documented tag toilets:num_chambers | Keys | OpenStreetMap Taginfo
This tag is used 30k times, and combinations with male/female and type of toilet are used about 40 times in total.
On the other hand: capacity:male:toilets does not exist at all capacity:male exists just 20 times plus 3 times in combination with further subkeys. capacity:toilets exists only 60 times
So, the proper tagging should make use of toilets:num_chambers.
In general it might be better to have shorter tags instead of long and very specific ones. As the male and female toilets are usually separated, it might make sense to have separate nodes for them and use e.g. toilets:num_chambers:seated on each of them.
Apart from the areas of import I can’t see any difference in geographical distribution.
I don’t see how the combination with building=* matters - almost every toilet is inside a building.
And many toilets are mapped as a sub-feature of another POI like a shop or restaurant.
toilets:number has, apart from the one import longer times of declining use which tells me it’s not in active use. toilets:num_chambers on the other hand has several thousand cases of individually added tags.
Anyhow, as both tags have not been proposed or discussed we should stay with the one that has a lot higher usage by individual mappers and at the same time the higher usage in total - toilets:num_chambers.
I understand that both “num_chambers” and “number” are largely derived from imports, and there is no consensus that the key is standard.
However, I also understand that it makes more sense to use “num_chambers,” which has a higher number of individual uses by people.
However, since there is no consensus on either option, we can consider their merits from perspectives other than the number of times they are used (such as whether they accurately correspond to the meaning of the word).
Chamber is a word that means something room-like. While sitting and squatting toilets generally have private rooms, urinals do not.
Therefore, “toilets:num_chambers:urinal” is unnatural, and mappers who consider the meaning of words important may choose to use “toilets:number:urinal.”
In my opinion, tag consistency is more important than being fully semantically correct.
In situations like these, I always opt for tags that fit into the most common current scheme, are not ambiguous and are self-explanatory. In the case of urinals, I think it’s clear what ‘num_chambers’ refers to, even if there are no separate chambers.
The good thing is that once we have some discussion or approved tagging, it’s simple to automatically change the existing tags to any new scheme.