Tagging opinions wanted for best practices… In Vaasa (Finland) there seems to be a boulevard (highway=secondary) that is converted to a highway=pedestrian for summertime - this is designated by official signage. The exact dates vary by year.
Currently it is tagged using a conditional motor vehicle access (motor_vehicle:conditional=no @ (29 May 2025 - 15 Sep 2025)). I feel this might not sufficiently convey the change, as the map will not exactly represent what is on the ground. After all, it is a highly walkable, leisurely and beautiful highway=pedestrian in summertime, not a highway=secondary with no motor vehicle access.
This was brought up by user theDagger in map note #4734710, where more details are found in the form of a linked article. Here’s the highway in question.
All the pleasant adjectives you used don’t make a difference. If there was only a barrier and/or a sign forbidding motor vehicles, then it would remain a highway=secondary, no matter how nice it is to walk there.
On the right, the sign disallows motor traffic, so motor_vehicle=no is correct.
On the left, there is a sign that is explained here:
On a pedestrian zone driving is allowed, but the speed must be adjusted to the pedestrians and cannot exceed 20 km/h. All drivers and cyclists must give unobstructed access to pedestrians.
I.e. the street legally becomes a pedestrian zone, so it is right to tag it as highway=pedestrian.
Then there remains the issue of what the conditional should contain. If it truly varies from year to year, the best option might just be to tag it with
I can’t imagine there’s many data consumers that would look at a highway:conditional tag. It looks like there are about 100 uses of it worldwide when you exclude the top two values which appear to be mistaken access:conditional.
Personally for that street based on the photo I would tag the access restriction for motor vehicles in the summer: motor_vehicle:conditional=no @ summer + foot=yes similarly as Jofban, and have map users figure out that they can freely walk on the roadway in the summer from that. (If legal status in Finland is foot=use_sidepath, I guess foot:conditional=yes @ summer instead.)
Sorry for the slight OT following…
Perhaps for cultural reasons, so far OSM generally doesn’t handle seasonal things very well.
The general approaches currently in use are:
map in “common” key namespaces with seasonal or intermittent as the only tags indicating conditionality, and have data consumers or map users guess the current state based on season. For example an ice rink tagged leisure=ice_rink + seasonal=winter + location=outdoor will be just a concrete pad in the summer, but it’s in leisure key which lots of consumers will try to read. Same with an outdoor swimming pool in the winter.
map in “custom” key namespaces to indicate their special status, effectively hiding the feature from any consumers that don’t explicitly look for it. For example Key:xmas:feature - OpenStreetMap Wiki
conditional tagging with various levels of support, and there are still open questions about which feature to tag as the “main” one (e.g. same real-world item being both a rollerskate rink leisure=pitch + sport=roller_skating, and an ice rink leisure=ice_rink + sport=ice_hockey - which tags get used?), or whether the seasonal features should be two OSM features, possibly with same geometry
