Poll: Interpretation of seasonal=* values

[ftrebien (Fernando Trebien)]

The wiki currently states that values such as seasonal=winter or seasonal=wet_season can be ambiguous.

When you see seasonal=wet_season, for example, on a river, an amenity or a road, what do you think it currently represents?

• The feature is present, active or available during the wet season
• The feature is absent, inactive or unavailable during the wet season
• The feature varies seasonally, but the tag does not specify its state during the wet season
• It depends on the type of feature (please explain)
• Current usage appears inconsistent, different mappers may mean different things
• Other (please explain)

Comments and examples from existing usage are welcome.

[jimkats]

For rivers, I would expect that the river is dry and gets water only during the wet season of the area. When is that season? That’s ambiguous. Although I would expect a different value to denote whenever there’s rain, because rains may occur during the whole year and not just during the normal wet season (i.e. winter).

For a road, I would suspect that the tag means, along with some other related tags, that it isn’t accessible when, for example there’s too much water when going through a waterway.

For amenity, I guess that tag would be used for an amenity related to the above, like a barrier made out of sandbags along the riverbank, that is installed during that season to prevent water overflow.

[Jarek]

My personal use of these tags (seasonal=winter on ice rinks, seasonal=summer on water play features) has been that the features exist or are functional during the given season.

But I can easily imagine other interpretations, and agree it can easily be ambiguous.

I generally consider seasonal=* to be a tag used more for communication with other mappers than for unambiguously encoding data.

E.g., I would expect to be able to understand a seasonal=* tag added in Canada by a Canadian mapper, but not necessarily a seasonal=* tag in Thailand.

[campbelltree]

@jimkats

For a road, I would suspect that the tag means, along with some other related tags, that it isn’t accessible when, for example there’s too much water when going through a waterway.

I think that this is the only critical ambiguity - mapping the tag as if it means that a road is inaccessible - and likely a good target for an education campaign or editor UI updates.

[ftrebien (Fernando Trebien)]

@jimkats

For rivers, I would expect that the river is dry and gets water only during the wet season of the area. When is that season? That’s ambiguous. Although I would expect a different value to denote whenever there’s rain, because rains may occur during the whole year and not just during the normal wet season (i.e. winter).

intermittent=yes probably applies in this case.

[ftrebien (Fernando Trebien)]

@Jarek

I generally consider seasonal=* to be a tag used more for communication with other mappers than for unambiguously encoding data.

In the case of a road that is seasonally inaccessible (for example, due to relatively predictable but inexact seasonal flooding), I imagine that, during those periods, a navigation app could alert the user if it calculates a route that includes such a road, or it could avoid it, perhaps depending on a user-configurable option.

In some regions of the world, these roads are clearly signposted, so access:conditional is applicable, but in other regions they are not, so access:conditional would be a bit of a stretch and, at best, an educated guess.

[Jarek]

@ftrebien

In the case of a road that is seasonally inaccessible (for example, due to relatively predictable but inexact seasonal flooding), I imagine that, during those periods, a navigation app could alert the user if it calculates a route that includes such a road, or it could avoid it, perhaps depending on a user-configurable option.

Personally I would tag that specific case as flood_prone=yes. An app could display that and the user might know when roads are most flood prone in that area.

@ftrebien

In some regions of the world, these roads are clearly signposted, so access:conditional is applicable, but in other regions they are not, so access:conditional would be a bit of a stretch and, at best, an educated guess.

Yes, point taken - we’d want a tag that would say “this is seasonally impassable” without specifying the exact nature of the impassability (like flood_prone)

Maybe you can take some inspiration from Key:winter_road - OpenStreetMap Wiki or Key:ice_road - OpenStreetMap Wiki ? Extrapolating from those, something like dry_season_road=yes doesn’t seem terrible.

[ftrebien (Fernando Trebien)]

Thank you all for the feedback. I’ve updated the wiki given the overwhelming consensus. Feel free to adjust it to clarify any nuances. The poll is still open and the article may need further revision later.