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, for example, 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. 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.
Illustration
Usage
Dense blocks of streets or other complex arrangements are not collapsed or thinned out. Consider using the Thin Road Network tool to reduce the density of streets.
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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 and collapse the circles after.
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.
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.
Syntax
Parameter | 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 is to 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 |
Code Sample
The following Python window script demonstrates how to use the CollapseRoadDetail tool in immediate mode.
import arcpy
from arcpy import env
env.workspace = "C:/data/cartography.gdb/transportation"
arcpy.CollapseRoadDetail_cartography("roads.lyr", "250 Feet", "roads_collapse_250")
Environments
- Reference Scale
The reference scale is only considered when the Collapse Distance parameter is entered in page units.