Example of reference points that are outside the span of a linear asset feature

Reference points such as mileposts are used to define other features, attributes, relationships, and work order spans. When the start and end points of an asset feature do not correspond to reference points, you can select reference points outside the span of the asset feature. Default values are used for the offset to ensure that the measurement is within the boundaries of the reference points.

Example

You create a linear asset such as a 100 mile train track. You add mileposts to the track at mile intervals to act as reference points. You label the mileposts MP 1 to MP 100. You create a guardrail as an asset feature. The guardrail starts at MP 10 with an offset of 250 feet, and ends at MP 10 with an offset of 500 feet. You create a guardrail classification with an attribute of MATERIAL because at a point along the guardrail the material changes from wood to aluminum. You can use MP 10 as a reference point, even though it is outside the span of the guardrail. If MP 10 is selected for the start or end measure of the MATERIAL attribute value, the offset defaults to 250. The default ensures that the calculated absolute measure is brought within the span of the guardrail asset feature. You can override the offset with the correct value. For example, the Wood value might start from MP 10 offset 250 and end at MP 10 offset 375. The Aluminum value would then start at MP 10 offset 375 and end at MP 10 offset 500.