Key:is_in:state
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Description |
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Indicates the state in which the feature is located (deprecated). Or distinguishes a relation representing a portion of a long-distance route that is divided along state boundaries. ![]() |
Group: boundaries |
Used on these elements |
Status: in use |
Tools for this tag |
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This key holds the name or abbreviation of the state (border_type=state
) in which the feature is located. On a route relation, it more specifically indicates the state-level scope of the relation. The latter usage is unrelated to is_in=*
.
Geocoding
Originally, this key appeared on a wide variety of features, as a crutch for geocoding software. This usage was deprecated along with is_in=*
. However, as of May 2025, it is still prevalent in South America and Asia, often due to imports.
Route disambiguation
Following the deprecation of is_in=*
, this subkey was repurposed for use on route relations that belong to super-relations. In this context, it distinguishes a relation representing a portion of a long-distance route that is divided along state boundaries. For example, in the United States, an Interstate highway is technically a series of connected state-administered routes that meet at state border crossings. A superrelation represents the entire interstate route as motorists would perceive it, while each of its members represents one leg of the route within a given state.
Another use of this subkey is to disambiguate identically numbered routes in the same network but in different states. For example, the Interstate system includes four routes numbered 275 (one of which consists of three state-level routes). is_in:state=*
distinguishes these completely unrelated routes by state. This metadata is not intended to be used in geocoding. Instead, it is intended for relation lists in editors and the like, preventing mappers from accidentally adding ways to the wrong relation.
As of May 2025, route disambiguation accounts for about 6% of all usage on relations, but it is much more prevalent in North America. It accounts for 93% of usage on relations in Canada and the U.S. and 88% in Mexico.
Alternatives
In general, it is no longer necessary to explicitly tag the names of the administrative areas that contain a feature. Instead, geocoders and analysis tools are expected to perform spatial queries (point-in-polygon tests).
Some route relations use addr:state=*
to disambiguate identically numbered routes, borrowing the key from the tagging scheme for street addresses. This has the advantage of avoiding confusion with the deprecated is_in=*
usage, but the disadvantage that technically these state abbreviations have nothing to do with addresses either.