|Used together with the higher-level tags like highway/building=construction to describe the type of feature which is currently under construction.|
|Used on these elements|
|Documented values: 6|
|Status: de facto|
|Tools for this tag|
This key is mostly used together with the tags building=construction, highway=construction, landuse=construction or railway=construction to describe the type of the feature which is currently under construction.
Major road and rail construction schemes typically take several years to complete. Use this key to denote active construction sites (for projects being planned, where there is little or no evidence of them on the ground, avoid tagging them or use proposed=* instead).
Already existing features may be closed for a short time for temporary construction (e.g., old, damaged roads getting rebuilt or a road closed over a weekend to replace a sewer pipe). Don't use construction=* to tag such short-term closures; consider using conditional restrictions instead. As OSM data is often used offline (and therefore may be several months old), only tag construction sites (particularly roads and railroads) if they are planned to be closed for at least six to nine months.
Use in well-defined combinations of building=construction, highway=construction, landuse=construction or railway=construction + construction=<value>. The value of the construction=* key should be one of those defined below and indicates the type of feature being built (you can use any value from highway=*, railway=* and building=*). For example: highway=construction+construction=primary describes a highway which is under construction and its type after the construction has finished will be
A deprecated option is to set the tag construction=yes. While this allows you to tag just about any feature as being "under construction", it breaks data for anybody not supporting it, and is therefore not recommended. A lifecycle prefix is usually the preferable alternative for such features.
If you know the date on which a construction site is expected to be completed, you can tag it with opening_date=*. Additionally, you can use check_date=* to denote when you last checked/updated the values. This can be useful as large construction projects are often delayed. For some construction projects the planned opening date may be unknown or difficult to ascertain.
Since the use of cascading tags as the standard for highways and railways is dominating, but lifecycle prefixes are used in other contexts, some are also adding the namespace approach to support possible future standardization and deprecation of current standard. For example construction:railway=tram.
In addition to using highway=construction, you should also tag the type of highway being built by using construction=*. For instance, to mark a primary road under construction, tag it with highway=construction and construction=primary.
|Motorway under construction
Motorway sliproad under construction
|Important non-motorway road under construction
Sliproad to an important non-motorway road under construction
|Primary road under construction
Sliproad to a primary road under construction
|Secondary road under construction
Secondary road link under construction
|Tertiary road under construction
Tertiary road link under construction
Unclassified road under construction
Residential road under construction
|living_street||Living street under construction|
|Road with unknown classification under construction
Raceway road under construction
|pedestrian||Pedestrianised road under construction|
|service||Service road under construction|
|Track under construction
Bridleway under construction
Cycleway under construction
Foot path under construction (alternative tag <construction=footpath>)
Path under construction
Steps under construction
Similarly to highways above, tag the railway under construction with railway=construction and the type of railway being built with construction=*. Some add also construction:railway=*. The following values for construction=* will render on Osmarender at zoom levels 14 and above:
|rail||Standard gauge railway under construction|
|narrow_gauge||Narrow gauge railway under construction|
|light_rail||Light-railway under construction|
|tram||Tramway under construction|
|preserved||Preserved railway under construction e.g. for steam trains|
|subway||Subway under construction|
|monorail||Monorail under construction|
When combined with landuse=construction, this tag can be used to specify what the landuse will be once construction is completed. Typically, these will be one of the common "developed land" values - for example construction=residential when mapping an under-construction housing development.
Since most construction sites are not accessible to the public, it might be tough to get detailed GPS tracks of roads which have not yet been built. In that case, it's sufficient to roughly trace the route, and increase the detail level once the road is open.