Linear Assets (4) – Asset Specifications

Last Updated on October 29, 2023 by maximosecrets

This article explores the Specifications tab on the Assets application.

Assets Application – Specifications Tab

A linear asset can be classified, and the classification can have a set of attributes that describe the asset. For example, a road may have an attribute of road surface, number of lanes, or speed restrictions. For a linear asset the attribute values may differ over various lengths of the asset.

The linear asset itself can have a classification, ROAD in this case, and a Specification, the attributes of the asset. When the asset is a linear record then the Start Measure and End Measure in the Specifications table window and the From and To in the header are displayed.

If you add a From and To measure in the header then this acts as a filter on the Specification records to show the attributes that have an End Measure greater than the From value or attributes that have a Start Measure less than the To value, i.e., they overlap either partially or fully with the From and To measures. In the example I have filtered by attributes that exist between 30.00 and 40.00 miles.

With the filter removed, I’ve sorted the table window by Attribute to make it obvious that the same attribute can have multiple records in the asset’s specification, and the Section attribute has not been used to achieve this. You can see that there are Alternate Names for I-95 at different segments along the linear asset, Capital Beltway, Ft McHenry Tunnel and John F. Kennedy Memorial Highway. The type of AREA changes from Suburban to Rural multiple times and there are five attribute records of COUNTY for the counties that I-95 crosses for this section of 109.70 miles. 

Each attribute has a Start and End Measure which may be the same if the attribute is of type POINT, otherwise for LINEAR they will have a distance between them. The attribute ELEV – Elevation, in the last row shown, is an example of a POINT type.

At the bottom of the Specifications tab is the linear visual control which is the best way to visualise the changes to the attributes across the linear asset. You can see where the Alternate Name (ALT NAME), AREA and COUNTY occur along I-95.

I’ve highlighted a POINT attribute; it is shown as a diamond. It is for the ELEV attribute, and the Balloon Tip Message shows an elevation of 312.0 FEET at 26.00 miles in from the start of the linear asset.

I’ll not show a screenshot of the Organizations application and Asset Options dialog again, but the Label and Balloon Tip Message can also be configured, in the record called Asset Specifications.

Assets Application – View Asset Specification History

You may be familiar with the View Asset Specification History dialog because it is available for non-linear assets and shows the changes to attribute values over time.

When the Linear add-on is installed, this dialog shows the Linear Segment Details section which we have seen before. I changed the attribute for ELEV – Elevation, from 312.0 to 312.2 and As of the current date and time it shows 312.2 FEET.

If I change the As of date and time to an earlier time you can see that as of 11/02/22 12:00 it was 312.0 FEET.

The Asset Specification History works as follows:

If you filter the Specifications table window, here I have filtered by the attribute “speed”. 

The Linear Visual Control is also filtered by the filtering you apply to the Specifications table window.

The SPEED attribute is an example of an attribute that is marked as Continuous, there are not supposed to be any gaps or overlaps along the linear asset.

Notice currently there is a SPEED attribute for the whole length of the linear asset, in three linear segments.

There is no splitting or merging of attributes with the same name and attribute value. Here I reduced the length of the first SPEED attribute from 55.00 to 50.00. Then overlapped the second SPEED attribute with the first by changing its Start Measure to 45.00. Then changed its speed limit from 45 to 65 mph to coincide with the first SPEED attribute’s numeric value. Finally, I created a 4th SPEED attribute the same as the 2nd SPEED attribute. There were no error or warning messages, you will end up with whatever data you create or modify.

After creating a gap in the attribute SPEED between 50-55 miles I ran the Linear Gaps and Overlaps Report, and it shows the Gap for the asset specification of the attributes marked as Continuous. The report section header indicates Attribute: SPEED Gap: 50-55.

The rest of the report is showing gaps and overlaps from the LANE feature which was illustrated in Linear Assets (3) – Asset Features. What there doesn’t appear to be is any part of the report which shows there is an overlap of the SPEED attribute between 45.0 and 50.0 miles. The gap between 50-55 was presumed to have been plugged by one of the SPEED attributes unless they have been ignored because the attribute value is the same as that for 0 to 50.0 miles. I’ll try and get IBM Support to work out how the report is supposed to work and whether this illustrates any issues. 

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