Essential Roads and Highways vocabulary


The steps in a workflow specific to performing an operation on an LRS Network.


Advanced linear referencing system as implemented in Roads and Highways.

Anchor point

A known location on the ground that is used for measuring linear features; serves the same purpose as a geodetic control point.

Anchor section

A precisely measured distance between two anchor points; does not necessarily contain actual GIS geometry (for example, vertices).


An event.

Business data

Nongeospatial data that can be referenced using route and measure values.

Calibration point

A GIS feature that represents a measure value along a given route for a specific LRS Network. Calibration points must have a measure value, a route identifier, and a network identifier.


The primary geometry from which routes are created.

Control section

The smallest granular unit of a route geometry, sometimes used as a synonym for Anchor Section and often referred to as a datum element.


As used in linear referencing, datum ties the linear referencing system (LRS) to known geographic locations on the ground. A datum element is a GIS feature that can be used to represent linear referencing method (LRM) measures.


A point or line layer that is referenced to a route by measure values.

Event behavior

The impact that changes in the highway system have on assets that are located relative to the highway being changed.


Global Positioning System.

Interpolative LRM

A linear referencing method that determines location by interpolating between two known measures.


The implementation of one or more workflows in Workflow Manager (WMX).

Linear Network Maintainer

GIS analyst responsible for editing the ALRS.

Linear Network User

GIS staff responsible for performing analysis, making maps, or conducting quality control on ALRS data.


The relative distance along a route from a known point of origin.

Location management

The process of controlling event behavior by prioritizing either location or position when the underlying network is modified.


Linear referencing method; a system for measuring highways and other linear features.


Linear referencing system.

LRS Network

A collection of routes in an ALRS.


A location along a route based on a distance from a known point of origin.


The United States National Highway System.


A fixed point on the ground having discrete x- and y-coordinates.


One or more jobs required to capture the work being done on the highway.


A markup feature that temporarily stores LRS information and communicates changes to a route.


A fixed location along a route that has a discrete measure value from which other locations are determined.

Referent LRM

A linear referencing method that determines location by measuring a discrete distance from a known location, or referent.

Referent offset

A fixed distance from a referent; can be positive or negative.

Roadway Inventory User

Non-GIS staff who use ALRS data to reference business data.


A linear LRS feature.


A collection of steps and activities required to complete a project.