Collapse Road Detail (Cartography)

Summary

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 roads from the input collection that are not collapsed will be copied to the output feature class.

Learn more about how Collapse Road Detail works

Tip:

This tool is generally used to simplify a relatively large-scale road collection at a smaller scale when 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 recommended that you run Collapse Road Detail first.

Illustration

Interruptions in a road network (such as traffic circles) are replaced with simplified connections that are smaller than the collapse distance, which is shown below the map in red.

Usage

• 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. You can run 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 Geodatabase Field Properties environment is not checked.

• Processing large road datasets may exceed memory limitations. In this case, you can process 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.

Parameters

Dialog

Label	Explanation	Data Type
Input Features	The input features containing small enclosed road details, such as traffic circles, to be collapsed.	Feature Layer
Collapse Distance	The diameter of, or distance across, the road detail that will be considered for collapse.	Linear Unit
Output Feature Class	The output feature class containing the collapsed features—features that were modified to accommodate the collapse—and all unaffected features.	Feature Class
Locking Field (Optional)	The field that contains locking information for the features. The data type must be short or long integer. A value of 1 indicates that a feature will not be collapsed.	Field

Python

arcpy.cartography.CollapseRoadDetail(in_features, collapse_distance, output_feature_class, {locking_field})

Name	Explanation	Data Type
in_features	The input features containing small enclosed road details, such as traffic circles, to be collapsed.	Feature Layer
collapse_distance	The diameter of, or distance across, the road detail that will be considered for collapse.	Linear Unit
output_feature_class	The output feature class containing the collapsed features—features that were modified to accommodate the collapse—and all unaffected features.	Feature Class
locking_field (Optional)	The field that contains locking information for the features. The data type must be short or long integer. A value of 1 indicates that a feature will not be collapsed.	Field

Code sample

CollapseRoadDetail example (Python window)

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

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

Environments

Cartographic Partitions, Reference Scale

Special cases

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