|Describes the primary usage of railways, pipeline or waterways|
|Used on these elements|
|Status: in use|
|Tools for this tag|
The distinction between main and branch line in general should be straightforward, but may be vague in certain circumstances; for example, if the branch line is very long. Some generic criteria are described in the table, below, but one should consider each case individually. Often, branch lines are described as such in the official name, however, sometimes rail is named "XYZ Main Line" even though it is more appropriately tagged usage=branch.
The distinction between the other types of usage should be more obvious.
A track that is tagged with usage=main or usage=branch should not also be tagged with service=*. Crossovers, yards, and sidings are tagged with service=*. (This does not apply for industrial, military, test and tourism railway infrastructure. These tracks may be tagged with both usage=industrial/usage=military and service=*).
Inside a railway station area, use usage=main or usage=branch only for the main tracks (not for siding, yard tracks etc.). That also applies for crossover or overtaking tracks outside of the railway stations.
|usage=main||Main line, presumably heavy traffic, often double tracked and/or electrified, may be high speed.|
Example: Rail lines left and right of the Rhine river
|usage=branch||Branch line, less traffic and lower speed than main lines, often single tracked and/or not electrified, may be constructed to lower specifications than main line. May connect a place to a mainline or serve to connect mainlines, typically a few dozen miles in length.|
|usage=industrial||Tracks in private use that serve only freight transport inside larger ports, industrial complexes/zones or mining areas, also for connection to the public network. In the USA, may serve factories or clusters of industrial activity along a rail spur in (often urban) industrial-zoned areas. |
Examples: Large surface mining areas (coal, minerals, ore), chemical industry, large harbours, high-density industrial oil refinery areas.
|usage=military||Tracks for military use, mainly on military areas, munitions storage areas or connections to the public railroad network.|
|usage=test||Tracks used for testing of new vehicles or new rail transport technologies.|
|usage=tourism||Tracks for tourists, around museums, historic or "heritage" trains, often only on weekends and holidays and/or seasonally, most preserved railways (railway=preserved and railway:preserved=yes)|
Examples: Mount Washington Cog Railway, Cumbres & Toltec Scenic Railroad, Roaring Camp Steam Train