Talk:Tag:traffic calming=island

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Possible alternative

Isn't it better to split the way and create two parallel ways, accurately describing the situation? --Jgpacker (talk) 13:16, 13 October 2014 (UTC)

What about drawing traffic islands as areas?

traffic_calming=island should be only used on nodes or ways.

On the other hand, when we have detailed aerial imagery, roads can be drawn more accurately, and traffic islands can become areas. I’ve come across area:highway=traffic_island (7,248 results in taginfo as of August 2018). Should we add a reference to this, as the recommended way to tag them when drawn as areas? Bxl-forever (talk) 09:30, 9 August 2018 (UTC)

Yes, we should retag all the areas Overpass-turbo.svg tagged with traffic_calming=island or traffic_calming=painted_island as area:highway=traffic_island. Davileci (talk) 17:12, 1 October 2023 (UTC)
Please see Discourse. (and avoid fragmenting discussion)
—— Kovposch (talk) 05:56, 5 October 2023 (UTC)


There is a suggestion to limit this to widths<5m, my suggestion would be to have only functional/geometric requirements: a traffic island (for pedestrians and or bicycles) between 2 carriageways of the „same“ street.—Dieterdreist (talk) 08:05, 14 May 2019 (UTC)

Splitting the highway

We should add a hint that it is preferable to tag it on an area and split the highway into separate carriageways.—Dieterdreist (talk) 08:05, 14 May 2019 (UTC)

I agree, physical barrier always makes separate ways. Tomasz W (talk) 05:23, 30 May 2019 (UTC)
I disagree, for a small traffic island that's only a two meters or so long we should not split into two oneway ways. There really is just one road here with a small traffic calming island in the middle. If highway ways represent the road centerline, that road centerline still goes through the island, as it's all just one road. Aharvey (talk) 12:54, 25 September 2019 (UTC)
I admit 2 meters seems very short (that's about 7 ft). When I think about short traffic islands they are more in the 5-15 meter range. Thinking about a 2m interruption in the middle of the carriageway, it would maybe be better represented as a "hole", rather than splitting the carriageway. Can you give a real life example for such a situation? Maybe traffic_calming=chicane would be more suitable for such tiny "islands"? --Dieterdreist (talk) 13:36, 25 September 2019 (UTC) (edit in iD and the default imagery you can see on the ground its about a car length of concrete, the rest is just paint on the ground). I think this is best mapped without splitting the way and instead using a single crossing:island=yes node on the road way to model what's on the ground. Without the split way, the road is straight (which better represents this road being straight on the ground). For example we don't split a footway to go around either side of a bollard, that would be silly and doesn't model what's happening on the ground, and so for short islands I don't think we should split the road to go around it either. For longer separations I think it's fine, but not for short almost node like islands. Aharvey (talk) 14:28, 25 September 2019 (UTC)
I would split the carriageway in such a case. It is about 50 meters of actually split carriageway (as drawn now) and about 35 meters length of the painted division, and there is a kind of physical separation (even if short). --Dieterdreist (talk) 21:44, 25 September 2019 (UTC)

different directions of traffic?

The definition says it must split 2 different directions of traffic. Why? What about traffic islands that split lanes in the same direction of traffic? --Dieterdreist (talk) 10:14, 10 December 2019 (UTC)

Why is this traffic calming?

Traffic calming implies a purpose. What about traffic islands set up for a different purpose, should they also get the tag, or are we to invent a different one? I.E. traffic islands in most situations are set up to facilitate the crossing of pedestrians, regardless of "calming" the traffic or not (e.g. in case of traffic lights, the island provides a relatively safe place for pedestrians, so that vehicular traffic can drive faster, the opposite of traffic calming). --Dieterdreist (talk) 10:14, 10 December 2019 (UTC)

The island will split the road in two so a six meter wide road will only be three meters wide where the island is. This will slow cars down. Also cars will be forced to slalom and that will slow them down too. --Accept (talk) 12:07, 10 December 2019 (UTC)
These are implementation details (how sharp the angle is for cars, if there is a sufficiently long "preparation" phase (road markings) and a gentle widening of the road, the cars will not have to slow down, it depends on the purpose, whether vehicles should be slowed down or not). Also the widening of a 20m wide road to 25 will be less noticable, or of a 10m wide road to 5+5. There is crossing=island and the newer crossing:island=*, but these are intended as properties for a crossing, not to represent the island (explicitly). --Dieterdreist (talk) 12:52, 10 December 2019 (UTC)
I would go as far as claiming that islands do not do any calming; instead, the calming effect is due to the road section featuring other obstructions or restrictions. –Jengelh (talk) 00:20, 1 October 2020 (UTC)

It would be useful to know if these are suitable for pedestrian crossing islands too TrekClimbing (talk) 07:48, 23 April 2021 (UTC)

Distinguishing between calming islands and circular junctions

In and, users changed roundabouts to traffic calming islands, and other users objected, suggesting circular junctions instead. The examples in Portland look similar to the example photo in Tag:traffic_calming=island#How_to_map. The wiki should give some guidance for how to choose between those options. Some considerations include:

  • When driving or biking, navigation software should not call out these intersections, as there's no reason for a driver or biker to wonder if the island means they need to turn. Marking them as roundabouts causes navigation software to call them out. Within OsmAnd, the "circular junction" at N 3rd St & E Younger Ave, San Jose does the same, while the "traffic calming=island" at N 2nd St & Burton Ave, San Jose is treated as a simple intersection.
  • It appears to be impossible to record that a tree is "inside" an island when that island is an attribute of a node, and a lot of these center islands do include trees.

--Jeffrey Yasskin (talk) 18:21, 7 July 2021 (UTC)

This monument has been destroyed multiple times due to its location in an island at the center of an intersection.
Navigation software should treat a roundabout (or other circular intersection) with a small enough radius as a conventional intersection. For example, OSRM sets the minimum radius of a roundabout at 15 metres (49 ft); any roundabout below that threshold gets a roundabout turn maneuver, which sounds like "Turn left onto Burton Avenue" (or nothing at all when there's no turn). [1][2] This software heuristic allows OSM to accurately model what's inside the traffic island (which after all could be much more notable than a tree), avoids confusing instructions to motorists and cyclists, and avoids the need for data hacks that optimize routing at the expense of renderers. – Minh Nguyễn 💬 06:57, 9 July 2021 (UTC)
Thanks for the explanation. I've applied it to Tag:traffic_calming=island#How_to_map, the traffic_calming=island entries in Template:Circular_and_widened_road_features, Tag:junction=circular#Implications_for_routing, and Tag:junction=roundabout#Implications_for_routing so that future people don't make the same mistake.

In parking lots

See also Talk:Tag:amenity=parking#Grass islands in parking lots. Jidanni (talk) 08:05, 25 August 2023 (UTC)