|The construction tag may be used for roads or railways under construction.|
|Used on these elements|
|Tools for this tag|
Major road and rail construction schemes typically several years to complete. Use this tag to denote active construction sites (for projects being planned, where there is little or no evidence for them on the ground, use proposed=* 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. Don't use construction=* to tag short-term closures (e.g. a road closed over a weekend to replace a sewer pipe); consider using conditional restrictions instead.
Use in well defined combinations of highway=construction, railway=construction, building=construction + construction=value. The value of the construction=* key should be one of those defined bellow and indicates the type of feature being built (you can use any value from from highway=*, railway=* and building=*).
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 won't be supported by the map renderers and other data consumers, and is therefore not recommended. A lifecycle prefix is usually the preferable alternative for such features.
If you know the date at 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).
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||Motorway under construction|
|motorway_link||Motorway sliproad under construction|
|trunk||Important non-motorway road under construction|
|trunk_link||Sliproad to an important non-motorway road under construction|
|primary||Primary road under construction|
|primary_link||Sliproad to a primary road under construction|
|secondary||Secondary road under construction|
|tertiary||Tertiary road under construction|
|unclassified||Unclassified road under construction (alternatively tag construction=minor)|
|residential||Residential road under construction|
|pedestrian||Pedestrianised road under construction|
|service||Service road under construction|
|track||Track under construction|
|bridleway||Bridleway under construction|
|cycleway||Cycleway under construction|
|footway||Foot path under construction (alternative tag <construction=footpath>)|
|steps||Steps under construction|
In all cases, the way will be rendered as a dashed version of the corresponding highway=* tag.
Similarly to highways above, tag the railway under construction with railway=construction and the type of railway being built with construction=*. 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|
In all cases, the way will be rendered as a dashed version of the corresponding railway=* tag.
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 usually sufficient to roughly trace the route, and increase the detail level once the road is open.
- proposed=*, for features which are being planned, but for which construction has not yet started.