A feature is a physical object, such as a guard rail or
mile marker, that you associate with one or more linear assets. The
main purpose of features is to locate the start and end points of
work locations along a linear asset.
Features are either of the point type or of the linear type.
- POINT: A point feature either has no length,
or its length is not related to its use with the linear asset. For
example, a mile post and a power line crossing are both point features.
The start and end measures for a point feature are the same.
- LINEAR: A linear feature has length, and
its length is related to the linear asset. For example, a guard rail
is a linear feature. Its length is described using the start measure
and the end measure along the road.
Identifying linear assets
You can
specify that a linear feature is continuous with a linear asset. A
continuous feature exists for the entire span of a linear asset. To
find gaps in continuous features, run the Gap and Overlap report.
You can associate a feature once or multiple times with a single linear
asset, and with multiple linear assets. Each association of a feature
with a linear asset creates a feature instance.
You can identify
a feature on a linear asset by measure and by label.
- Measure: Locate any feature by using a
combination of its feature name and its start and end measures. For
example, a road has a guard rail from mile 24.5 to 24.8, and another
from mile 27.0 to 27.7.
- Label: Features can have labels, such as
MP23, for mile post 23. Although labels are not always required, use
labels in the following situations:
- When multiple instances of the same feature are at the same measure.
Labels differentiate between the feature instances.
- When you plan to use the feature as a start or as an end reference
point to locate work. Reference points must be identifiable by maintenance
workers in the field. For example, a label can be the visible text
on a sign, or a well-known point of interest, such as a named hilltop.
A label can also describe a relationship with another asset or or
with another location, such as an intersection or rest area.
- When you want to perform work on the feature. The feature must
be identifiable in the field, which requires some form of visible
label. If you do not want to label every feature, create a single,
labeled feature for the entire asset, such as "All Guard Rails."
- Features can be shared with related linear assets. For example,
a single feature instance, such as a mile post, might be located between
two linear assets. If you define the feature as shared, the feature
appears on the records of related linear assets when the relationship
span includes the location of the feature instance. A relationship
span is that part of each linear asset over which the relationship
exists. For example, route 27 has a parallel relationship lasting
one mile with an access road. The relationship span runs from mile
8 to mile 9 on route 27, and from mile 0 to mile 1 on the access road.
You use the Relationships application to define the relationships
between linear assets. Define features as reference points. For example,
to identify work locations. Some features are not suitable as reference
points. For example, you can use pavement as a feature that spans
the length of a road, but you would not use it as a reference point.
You
use the Classifications application to create classifications of features
and define attributes for them as follows:
- Create classifications of features. For example, you can create
a class called Linear Features, with subclasses Guard Rails, Road
Surface, Mile Markers, and so on. Divide each class into subclasses
as needed.
- Associate attributes, such as height, width, and material, with
classes. When you specify a classification on a feature record, you
automatically import the attributes for that class.