|man_made = pier|
|A pier is a raised walkway over water, supported by widely spread piles or pillars.|
|Rendering in openstreetmap-carto|
|Group: Man made|
|Used on these elements|
|Status: de facto|
|Tools for this tag|
A pier is a raised walkway over water supported by pillars made of metal/wood, or floating and secured using chains (see wikipedia:Pier). Also referred to in some places as a 'jetty', 'raft' or 'dock'. The definition of "pier", according to the International Hydrographic Organization, is "a long, narrow structure extending into the water to afford a berthing place for vessels, to serve as a promenade, etc."
Piers can range in scale from very light structures providing a small pedestrian walkway, through to large solid structures with fixed piles extending over a mile out to sea.
Use man_made=breakwater for a solid structure designed to protect a harbour from waves and man_made=groyne for one designed to protect the shore from long-shore drift. For "piers" following the coastline, consider man_made=quay instead.
How to map
The simplest way to map a pier is as an open way tagged with man_made=pier for the length of the pier. To allow data users to render piers proportionally on different zoom levels piers can be tagged as areas . Mapping piers as an area is useful for both small and large piers; small piers tagged as open ways are often rendered too large, giving an incorrect impression of the distance between piers. If it makes sense connect the shore end of the pier to the coastline. Use shared nodes where piers connect to other piers over the water.
Lastly, connect the pier with other ways on land, otherwise it will result in a "island" that can't be used for routing. Create a highway=footway (or similar) from the pier's last node on land to nearby roads or other pedestrian ways as needed until it is connected to the main road/pedestrian network.
If passengers wait for ferry lines at this pier and if the ferry routes are mapped as public transport relations:
- add public_transport=platform on it
- add the object to the ferry route relations, with the platform role
- Marine Mapping
- on Wikipedia
- Proposed features/Seaway
- International Hydrographic Organization, IHO Dictionary, S-32, 5th Edition
- aerial photo of pier where substantive part is over land: https://www.abc.net.au/news/image/10370420-3x2-700x467.jpg
Possible Tagging Mistakes
A pier is a linear feature, "bridging" land and water, and can be mapped as a line or an area. Avoid mapping it as a node, because length and orientation are significant information, even if estimated.