Openstreetmap-carto: Add rendering for roller_coaster

[geozeisig]

The track should be mapped with roller_coaster=track. An example is this and there are even more next door. A narrow black line should be drawn on the map. At the moment, unfortunately, many use railway=* to get the track rendered. On the Key:attraction-page this is expressly disapproved (_Do not tag them as any railway!_). Since the track is meandering the name should not be placed here.
For the attraction, another node or area should be drawn on which the name stands. The name should be added in black. You could also add tourism=attraction, but that would be too much importance to the roller coaster.

[kocio-pl]

I guess for this rare type of objects it's enough for rendering with 920 uses:

https://wiki.openstreetmap.org/wiki/Tag%3Aroller_coaster%3Dtrack

[matthijsmelissen]

I think this is quite specialized, and I'm not sure about rendering it on a general purpose map.

[Adamant36]

@matthijsmelissen, personally id disagree. They aren't any specialized then other similar things like racing tracks or water slides that are already rendered. Also, they can take up fairly large areas, where you can't go under or around them safety reasons. So without rendering them your essentially advocating for large blank spots, that look like places people can go when they aren't.

Not to mention as the issue states anyway, they are already being rendered through wrong tagging anyway. So its just fixing miss-tagging if nothing else.

[pkoby]

On the Key:attraction-page this is expressly disapproved (_Do not tag them as any railway!_).

The https://wiki.openstreetmap.org/wiki/Tag:tourism%3Dtheme_park#Related_tags page lists railway=narrow_gauge as what is to be used until railway=roller_coaster is a thing. So I guess one of those pages should change (probably this one?).

[HolgerJeromin]

They are quiet big and good for orientation.
A full mapped theme park would look empty without a rendering.

[polarbearing]

Summer toboggan #3436 and Rollercoaster #3596 should be considered together. The carriageway could be rails, an ice or a water channel, for which all the same kind of line can be rendered.

Question is if we need an icon, and how the ground is rendered where the carriageway is built on.

[matkoniecz]

I would consider rendering track with one of railway styles. In the ideal world it would not be shown on general purpose map but unfortunately tagging for renderer is extremely popular here.

Unfortunately, it seems that choice is between "render roller coaster track" and "render roller coaster track mistagged as railway".

[meased]

We already render railway=miniature, and a roller coaster track pretty much is a miniature railway.

[jeisenbe]

it seems that choice is between "render roller coaster track" and "render roller coaster track mistagged as railway".

True. And roller coasters should not be rendered so early as railways. The mistagged examples look very strange at mid-zoom levels.

[filips123]

@meased

Do not tag them as any railway!

As you said, a roller coaster track pretty much is a miniature railway. So you could just render roller_coaster=track similar to railway=miniature.

[jeisenbe]

I've looked into the use of attraction=roller_coaster and roller_coaster=track in the context of deciding what tags to import as polygons during the next database reload. Both tags are frequently used to tag the tracks of roller coasters. Attraction=roller_coaster is mapped as an unclosed way 1,572 times (8-April-2019) and roller_coaster=track has 1483 uses on unclosed ways, so the two methods of tagging are about equally popular.

For rendering the track there is no problem about the database, because ways are imported as linestrings by default. If we want to render the label of the attraction based on polygons, this would require a change, however.

I would recommend that @geozeisig reopen the proposal process for roller_coaster=track with a RFC (request for comments) on the tagging mailing list, and then get it voted on. Then we might need to wait till roller_coaster=track is clearly the more popular choice (assuming that this is accepted by the community)

One issue to consider is how the routes of other types of attractions should be tagged and rendered. Currently, "attraction=dark_ride", "=river_rafting", "=summer_toboggan", "=train", "=water_slide" and "=slide" are usually mapped as open ways and the ID editor supports this for all except slide (and roller_coaster).

River_rafting and water_slide are often mis-tagged as waterway=canal for rendering, and it would be good to develop a rendering that would discourage this practice.

In particular, attraction=train might need to be considered along with roller coasters, but it's unclear what this tag means.

[jeisenbe]

I'd support using the same rendering at railway=miniature since both features are usually tourist attraction railways which loop around in a small area. That tag renders at z15 currently, but it's possible that roller coasters should not render until z16. This would need testing.

However, as I mentioned above, we should clarify if roller_coaster=track is the preferred mapping method for this feature, rather than using attraction=roller_coaster on the tracks.

[jeisenbe]

Now 2/3rds of ways are double-tagged with roller_coaster=track + attraction=roller_coaster - 2062 ways compared to 2800 unclosed ways for both tags individually. I'm not sure why they are being double-tagged in this way, @geozeisig do you know?

[geozeisig]

I can not explain it either. The wiki is clear. Now I asked a couple of people why they do it that way.
If roller_coaster=track not rendered I understand that railway=* is added. When the topic is solved we will have to revise the data again.

[DaveF63]

I support the rendering of this feature. They are contained within specific areas so no overlapping with other 'general purpose' features. Miniature railways & waterslides, of similar size & locations are already rendered. Using the same render as railway=miniature way seems appropriate, but with a 'bridge' style edging to indicate it is elevated.

[geozeisig]

There are now more than 3,500 applications

[DaveF63]

@geozeisig And that's only the correctly tagged ones. There are many falsely tagged as railway=* to force the rendering.

[Adamant36]

@geozeisig And that's only the correctly tagged ones. There are many falsely tagged as railway=* to force the rendering.

There's 87 instances of attraction=roller_coaster + railway=miniature. Which isn't to many, but it would still help if they were tagged correctly and there's probably more out there without the attraction tag.