Calculate Influence Ranges


Influence range examples for point and polygon BIHO features


Calculate Influence Ranges calculates the ‘influence ranges’ of Buildings Intended for Human Occupancy (BIHOs) on the centerline in preparation for ‘sliding range’ calculations subsequent to Class Location determination (as specified in 49 CFR §192.905). In the Class Location workflow, the sliding range is one mile in length. The ‘sliding mile’ for a BIHO feature starts at either end of the influence range for the BIHO. The endpoints of an influence range are defined by the closest distance point on the centerline straight-line segment(s) nearest to the BIHO feature, as shown in the above illustration.

For an example of how the ‘sliding mile’ is applied in the Class location workflow, see the Pipeline and Hazardous Materials Administration (PHMSA) letter of interpretation #PI-14-0017. #PI-14-0017 depicts the simplified situation shown in the above illustration, example a), where the influence range for a point BIHO feature collapses to a point location on the centerline. As the illustration shows, in more complex situations, the influence range for a BIHO becomes a linear range along the pipeline centerline. See How Calculate Influence Ranges works for more information about calculating BIHO influence ranges.


  • Input Structure Segment Features – This tool requires as input the DOT_STRUCTURESEGMENT features output by the Prepare Structure and Site Buffers and Segments tool. Unless otherwise specified, the tool defaults this parameter to the DOT_STRUCTURESEGMENT feature class in your selected Gas HCA Tool project geodatabase.
  • Output Influence Range Layer – Unless you specify otherwise, the default destination for the output influence range features is the DOT_BIHO_INFLUENCE_RANGE feature class in your selected Gas HCA Tool project geodatabase.
  • In a typical Class Location workflow, Calculate Influence Ranges is generally run after Prepare Structure and Site Buffers and Segments and before Prepare Cluster Buffers and Generate Sliding Ranges.


InfluenceRangeTool_hcapy (project_database, {structure_segment_layer}, {influence_range_layer})

Parameter Explanation Data Type

Dialog Reference

Select a Gas HCA Tool project geodatabase created using the Initialize Database tool. The output from this tool is stored in this workspace.

There is no Python reference for this parameter.




Dialog Reference

Specify your input BIHO segment features.

There is no Python reference for this parameter.

Table View



Dialog Reference

Specify the destination of the output BIHO influence range features.

There is no Python reference for this parameter.

Table View

Code sample

# Import GasHCA Library
import hcapy
# import Gas HCA Tools
arcpy.ImportToolbox(“C:\Python27\ArcGIS10.6\Lib\site-packages\hcapy\esri\Toolboxes\Gas HCA Tools.pyt”)
project_database = r”C:\projects\GasHCA_Enhancements\A_DOTCLass_Test5.gdb”
# Execute tool


Current Workspace, Scratch Workspace, Default Output Z Value, M Resolution, M ToleranceOutput M Domain, Output XY Domain, Output Z Domain, Output Coordinate System, Extent, Geographic Transformations, Output has M values, Output has Z values, XY Resolution, XY Tolerance, Z Resolution, Z Tolerance

Licensing information

This tool requires a valid Gas HCA Tool user license or subscription. Please see the Request License and Register License tool help topics for details on obtaining and registering a Gas HCA Tool software license.

Related topics


BIHO, Class Location, sliding range, sliding mile, influence range.


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Use limitations

There are no access and use limitations for this item.