Key:area

The area=yes tag is required for some closed ways when used to define an Area (polygon); however, for closed ways with other tags there is an assumption that the way defines an area. In some circumstances a closed way may define both a closed polyline and also an area.

Areas can also be described using one or more ways and a relation:multipolygon relation.

If the assumption that a closed way together with other tags defines an area is misleading, area=no can be used to clarify the situation. E.g., leisure=track, sport=running, area=no is just a closed running way.

Important note: a closed way only tagged with area=yes and name=* means nothing in OSM, although it might be rendered on maps by accident.

Used on these elements explained with symbols

for nodes the key area is not used
for open ways the key area is not used
for closed ways the key area can be used. A closed way without key area or with tag area=no it will demonstrate a , otherwise if a closed way has the tag area=yes it will be demonstrate a area
for relations area is not used - multipolygons are also marking objects as an area, so area=yes on them would be redundant

Summary

The following closed ways should be treated as linear features:

• barrier=*, for thicker hedges or walls or detailed mapping defined using an area add area=yes
• highway=*, see 'Highway areas' below for more details
• This list is probably incomplete - please add other cases

Closed ways are assumed to be areas in most other situations, including:

• aeroway=*, avoid using closed ways for aeroway=taxiway or it will be shown as an area
• building=*
• landuse=*
• leisure=*
• natural=*
• indoor=corridor
• …

Note that mappers frequently use multiple tags on the same closed way. This can result in the way being used to define both, an area and also a polyline at the outline of this area. For example a closed way tagged landuse=grass and barrier=fence can be interpreted as a fence enclosing an area of grass.

A clean solution would be to create one element for each feature. I.e. tag the closed way with linear feature tags only and add it to a multipolygon to map areas.

See also overview of what is can be considered as implying area status.

Highway areas

Pedestrian areas (for example squares and piazzas) should be formed using a closed-way around the perimeter and be tagged with highway=pedestrian and also area=yes.

Where a road crosses a pedestrian area then a linear way tagged in the usual way should be overlaid across the square. This linear way should shares nodes with the pedestrian area at its entrance and exit from the square.

In the context of roads, area=yes indicates that an area has no street lines within it (i.e., there is no given direction on the area).

Note: There is currently no clear agreement on how highway tag values other than pedestrian should be treated when also tagged with area=yes.

Note: Most pedestrian routing algorithms do not currently route (correctly) across area features, tending to route around the edge or not at all (especially in case of multipolygons). Do not alter your mapping to accommodate such routers.

Proposals

• Proposed features/area:highway – A tag to define the two dimensional area of highways.
• Proposed features/Street area – Notation of roads as surfaces and mapping details.

See also

• Sophox query for unclosed areas
• Stairs modelling: area=footway & area=steps