Creating a linear referencing method

You must create at least one linear referencing method before you can start working with linear assets. A linear referencing method (LRM) determines the position of a linear asset, based on a start point, a measure, and a direction.

About this task

To configure a linear referencing method, you specify units of measure for the length of the linear asset and for three offset measures. You can define multiple linear referencing methods, but you can apply only one of them to an individual linear asset. You cannot modify a linear referencing method after you add it to an asset.

Procedure

  1. From the Select Action menu in the Assets application, select Add/Modify Linear Referencing Methods.
  2. Click New Row.
  3. Enter values in the following fields:
    Option Description
    LRM Identifies the linear referencing method.
    Unit of Measure The unit of measure used to measure the length of the linear asset, for example miles or kilometers. The unit of measure must exist in the database.
    Base Unit of Measure By default, this field uses the value in the Unit of Measure field, but you can specify a different value.
    Offset Unit of Measure The unit of measure for the start and end reference points of the linear asset. The unit of measure for a linear asset can be miles, for example, but you can use feet to measure distances from a reference point, such as 300 feet from Mile Post 12.
  4. Optional: You can also specify values in the following fields:
    Option Description
    Y-Offset Unit of Measure The perpendicular distance from the linear asset, for example, a speed limit sign located 10 feet from the right edge of a road.
    Z-Offset Unit of Measure The distance above or below a linear asset for example, an exit sign located 18 feet above the surface of the road, or a culvert located four feet below the surface of the road.
    Y Reference The point from which the Y offset is measured, for example, a stop sign is located not just 20 feet from a road, but 20 feet from the midline of a road.
    Z Reference The point from which the Z offset is measured, for example, an exit sign is located 18 feet above the road surface, or a culvert is 12 feet below the road bed.
  5. Click OK.