Splitting Roads at intersection for ArcGIS Network Analyst?

Question

I have a file geodatabase Feature Class representing the roads of a city. The Roads are not split at Intersections. ArcGIS needs roads to be split at the intersections, otherwise it assumes that the roads are not connected.

This Image shows the Connectivity model for ArcGIS Network Analyst, when the roads are not split.

How do I correct this problem and split the roads wherever they intersect?

Answer 1

The Feature To Line (Data Management) geoprocessing tool can be used for 'cleaning up' the data.

The help file mentions:

Where input lines or polygon boundaries touch, cross, or overlap each other at locations other than their start and end vertices, they will be split at those intersections; each of the split lines will become an output line feature. If an input line or polygon boundary is not intersected by another feature, its entire shape will still be written out as a line feature.

In Addition, remember to set the Preserve attributes option to true, in order to preserve the attributes in the output file.

Answer 2

You can use the Planarize Lines tool in ArcGIS (ArcEditor or ArcInfo license is required).

Keep in mind though that you would lose the overpass/underpass information in this case since all the intersecting lines will be splitted. More general reading on splitting lines is available here.

Answer 3

ET GeoWizards has a split Polyline with Layer tool that might work for you. It requires the polyline layer you want to split (creates a new shapefile or feature class) and a layer that it uses to split the lines. I used it to split pipes (polyline) into zones (polygon) and it worked nicely but it works with two polylines as well.

If all your roads are part of one shapefile/feature class you should be able to add it twice to your mxd and rename one. ie roads1 and roads2 and then use roads1 to be split and roads2 to define were the first is to be split. I haven't tried this so hopefully it works in practice as well as theory.

Answer 4

This would work in PostGIS, but i have read that ArcGIS has SQL interface too. This one selects. Use 'select into' if you want to save data and add sequence for primary key

select * from (select r.id , st_Dump(ST_Split(r.the_geom, r2.the_geom))
from table road as r , road as r2 
where r.id != r.id AND ST_Intersect(r.the_geom, r2.the_geom)) as stuff

that should return data like

|id|geom|
--------
|1 |xxxx|
|1 |yyyy|
|2 |zzzz|

if i didnt do any mistakes

Answer 5

Using Planarize to split lines at intersections

1. In ArcMap, click the Edit tool Edit tool on the Editor toolbar.
2. Select the line features you want to split at intersections.
3. Click the Planarize Lines button Planarize button on the Topology toolbar.
4. Click OK.

The lines are split into new features where they intersect.

Attention: In Arc 10 and upper this tool is on the Advanced Editing toolbar.

Answer 6

From ESRI desktop help. The link is at the bottom and there is more than one possible approach.

"Polygons from the geometry of other features

1.In ArcMap, click the Edit tool on the Editor toolbar.

2.Select the features whose geometry you want to use to construct new polygon features.

3.On the Editor toolbar, click the Task drop-down arrow and click Create New Feature.

4.On the Editor toolbar, click the Target drop-down arrow and click the polygon feature class in which you want to create a new feature. The selected features and the target layer cannot be from the same feature class.

5.On the Topology toolbar, click the Construct Features button .

Optionally, type a cluster tolerance.

6.Choose whether to create new polygons from the selected features, to create new polygons considering the boundaries of existing polygons as input geometry, or to split features where selected lines or polygons cross them.

7.Click OK.

The new features are created in the target feature class."

http://webhelp.esri.com/arcgiSDEsktop/9.3/index.cfm?TopicName=Making_new_features_with_topology_tools