Collapse Road Detail (Cartography)


Collapses small, open configurations of road segments that interrupt the general trend of a road network, such as traffic circles, and replaces them with a simplified depiction.

Configurations are collapsed regardless of road class if the diameter across the open area is less than or equal to the Collapse Distance parameter value. All uncollapsed roads from the input collection are copied to the output feature class.

To learn more, see How Collapse Road Detail works.


This tool is generally used to simplify a relatively large-scale road collection at a smaller scale, where it is appropriate to depict traffic circles or other small interruptions to the network as a simple intersection. At medium scales, it may be preferable to retain these configurations as separate features and possibly exaggerate them. In that case, consider using the Resolve Road Conflicts tool instead to ensure that symbolized lines are displayed without symbol conflicts. If both Resolve Road Conflicts and Collapse Road Detail tools will be run on the same collection of roads, it is advisable to run Collapse Road Detail first.


Two examples of Collapse Road Detail tool results using different collapse distances
The Collapse Road Detail tool uses a collapse distance (shown as bars below the sample map images) to remove small interruptions in a road network.


  • Dense blocks of streets or other complex arrangements are not collapsed or thinned. Consider using the Thin Road Network tool to reduce the density of streets.

  • Circles, or similar open road details, that are connected to divided roads are not collapsed to avoid creating very small road segments. Consider running the Merge Divided Roads tool first to create a single road; then collapse the circles.

  • If a circle or other open road detail cannot be modified without impacting network connectivity, collapse does not occur.

  • Consider running this tool more than once at different collapse distances to create output suitable for different scales.

  • Domains and subtypes are copied to the output even if the Transfer field domain, subtypes and attributes rules environment is not checked.

  • Processing large road datasets may exceed memory limitations. In this case, consider processing input data by partition by identifying a relevant polygon feature class in the Cartographic Partitions environment setting. Portions of the data, defined by partition boundaries, are processed sequentially. The output feature class is consistent at partition edges.


CollapseRoadDetail(in_features, collapse_distance, output_feature_class, {locking_field})
ParameterExplanationData Type

The input features containing small enclosed road details, such as traffic circles, to be collapsed.

Feature Layer

The diameter of, or distance across, the road detail that will be considered for collapse.

Linear Unit

The output feature class containing the collapsed features—features that were modified to accommodate the collapse—and all unaffected features.

Feature Class

The field that contains locking information for the features. A value of 1 indicates that a feature should not be collapsed.


Code sample

CollapseRoadDetail tool example (Python window)

The following Python window script demonstrates how to use the CollapseRoadDetail tool in immediate mode.

import arcpy
arcpy.env.workspace = "C:/data/cartography.gdb/transportation"
arcpy.CollapseRoadDetail_cartography("roads.lyr", "250 Feet", "roads_collapse_250")


Reference Scale

The reference scale is only considered when the Collapse Distance parameter value is entered in page units.

Licensing information

  • Basic: No
  • Standard: No
  • Advanced: Yes

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