ARM and SRMP Locations Along Washington State Highways (2025)

A unique Route identifier to identify a route (City,County State, Tribal, Forest) in any given data set. For State Routes, Route IDs are assigned by WSDOT's GIS and Roadway Data Office

The measure of a point along the length of a route in which the distance is measured as an accrual of mileage from the beginning of the route

A logical number, assigned by a Linear Referencing Method, to a given point along a State Route. This value will always match the Accumulated Route Mileage value unless there has been a realignment or a jurisdictional transfer which changes the length of a route.

The distance of a point northward from a given base line indicated by a map grid reference, calculated in US Survey Feet.

The distance of a point eastward from a given meridian indicated by a map grid reference, calculated in US Survey Feet. Easting is used in State Plane Coordinate Systems

Latitude is a north-south measurement of position on the Earth. It is defined by the angle measured from a horizontal plane located at the Earth's center that is perpendicular to the polar axis. A line connecting all places of the same latitude is termed a parallel. Latitude is commonly, but not exclusively, measured in degrees, minutes, and seconds. Measurements of latitude range from 0° (at the Equator) to 90° North (90.0) or South (-90.0).

 Longitude is a west-east measurement of position on the Earth. It is the angle measured from a vertical plane running through the polar axis and the prime meridian at Greenwich, UK. A line connecting all places of the same longitude is termed a meridian. Longitude is commonly, but not exclusively, measured in degrees, minutes, and seconds. Measurements of longitude range from 0° (Prime Meridian) to 180° West (-180.0) or 180° East (180.0) from this point.

The number assigned to the State Route and enacted into law by the Washington State Legislature

A Code that represents a a classification of a route associated with a mainline state route, examples include: Couplet, Spur, Alternate Route, etc. 

A reference used to uniquely identify the physical location of the State Route Related Route Type. The State Route Related Route Qualifier can be based on a State Route Milepost, street name, city, or other distinguishing geographic reference.

An indicator that denotes if the Milepost is within a back mileage equation area. A back mileage equation area occurs when a segment of a route is added at any point other than the end of an existing route, or when a realignment occurs.

A code that represents whether the transportation asset or project is located in the (I) Increasing Milepost Direction of Travel, (D) Decreasing Milepost Direction of Travel or, (B) Both Milepost Directions of Travel.

An arc of the horizon measured between a fixed point (as true north) and the vertical circle passing through the center of an object usually in astronomy and navigation clockwise from the north point through 360 degrees

The Linear Referencing System date that this record is using for location.