This script compares two .net.xml files. The call

python tools/net/ diff

will produce 4 plain-XML network files:

  • diff.nod.xml
  • diff.edg.xml
  • diff.con.xml
  • diff.tll.xml

These files contain groups of xml elements (i.e. nodes) that have been deleted, created, or modified and can be used to investigate differences between the two networks A and B. Furthermore, these files can be used to maintain change-sets for making repeatable modifications:

netconvert --sumo-net-file -n diff.nod.xml -e diff.edg.xml -x diff.con.xml -i diff.tll.xml -o

The above call can be used to recreate network B based on A and the recorded change-set. Note, that for any modified elements (i.e. modified speed limit for an edge), the file diff.edg.xml only contains to modified attributes.

A typical use case for is this:

  1. Import a network from OSM (call this
  2. Make some modifications with netedit (save this under the new name
  3. Use to create the diff-files
  4. At a later date, re-import the OSM network (with a newer OSM file, a new version of netconvert or different options)
  5. Re-apply the diff-files to avoid repeating manual corrections with netedit

patching on import#

If the patch file is to be applied during the initial network import (e.g. from OSM), the netdiff option -i must be set. Due to the way connections are guessed during network import, all connections for an edge must be included in the patch file if any of them were changed. This is accomplished by setting -i (--patch-on-import).

patching a network different from the original#

Sometimes it may be useful to apply the difference between networks A and B to another network C than differs slightly from A. In this case it may be useful to only consider some of the changes (i.e. only created elements).

If only the newly created elements in B (relative to A) shall be considered, open each of the difference files (ie. diff.edg.xml, diff.nod.xml, diff.con.xml, diff.tll.xml) and keep only the elements below the heading

<!-- Created Elements -->"

This way the patch should be applicable to network C regardless of how it differs from the original A.

Sometimes, errors may occur due to inconsistent connections or traffic lights. In this case, it may be useful to only update C with 'diff.nod.xml and 'diff.edg.xml' and let netconvert guess the respective connections and traffic lights.

In the end all regions where the area of C and B borders each other should be checked manually for consistency.

This script generates additional connections for roundabouts from a given network. The following connections are added:

  • vehicles can stay inside of the roundabout on every lane.
  • vehicles can leave a roundabout even if they are driving on an inner lane if there are enough outgoing lanes.


python tools/net/ <net-file>

This creates the output file roundabout-connection.con.xml, where the input network is <net-file>.

This tool checks the network (first parameter) for weak connectivity (whether there is a route from every node to every other node, regardless of edge direction) and prints the connected components if not.

Additionally, you may run this script to discover which edges are reachable from a particular edge.

python tools/net/ <net-file> --source <edge_id> --selection-output selection.txt

This will create a file called selection.txt which can be loaded in sumo-gui to visualize the portion of the network reachable from <edge_id>. To visualize the selection, you must load the file via Edit->Edit chosen. Then, you need to enable edge coloring by selection status in the view settings dialog Street->Color by: selection. The reachable portion of the network will be colored differently from the unreachable portion which is usually sufficient to figure out network modeling errors.

The options can be shortened to -s <edge_id> for source edges and -o <filename> for selection output.

Using option --destination <edge_id>, or -d <edge_id>, lists edges which can reach the given edge. By adding the option --vclass <vClass>, or -l <vClass>, the check becomes vClass-aware.

The option --component-output <filename>, or -c <filename>, writes all the identified components and their constituent edges to the specified file. The option --results-output <filename>, or -r <filename>, writes the whole network summary of largest component percentage coverage and component edge count distribution to the specified file.

The --component-output and --results-output options are not compatible with the --destination or --source options.

Use the option --help for the latest version information. and

Both tools apply the given offset to the geometrical information of edges or nodes given in the input file. The results are written into <XMLEDGES>.mod.xml or <XMLNODES>.mod.xml, respectively.

python tools/net/ <XMLEDGES-FILE> <X-OFFSET> <Y-OFFSET>
python tools/net/ <XMLNODES-FILE> <X-OFFSET> <Y-OFFSET>
  • <XMLEDGES-FILE>/<XMLNODES-FILE>: The edges/nodes file whose content shall be shifted
  • <X-OFFSET>: The x-offset to apply
  • <Y-OFFSET>: The y-offset to apply

Reads edge id replacements from "edgemap.txt"; the format of this file is:


Reads the given connections file <CONNECTIONS-FILE> and replaces old edge names by the new ones. The result is written to <CONNECTIONS-FILE>.mod.xml

python tools/net/ <CONNECTIONS-FILE>
  • <OLD_EDGE_ID>: Id of an edge as used within <CONNECTIONS-FILE>
  • <NEW_EDGE_ID>: Id of the edge to use instead
  • <CONNECTIONS-FILE>: The connections file to change

converts '.net.xml' road geometries to KML format.

python tools/net/ -n <net-file> -o output.kml

By default, normal edge geometries will be exported. This can be changed with options

  • --lanes: write lane geometries
  • --internal: write junction-internal edges or lanes

converts '.net.xml' road geometries to GeoJSON format.

python tools/net/ -n <net-file> -o output.geojson

By default, normal edge geometries will be exported. This can be changed with options

  • --lanes: write lane geometries
  • --internal: write junction-internal edges or lanes

Generates an .edg.xml patch file with split definitions to ensure that each public transport stop of the given type (default <trainStop>) is on a separate edge from every other stop. The tool also generates an updated .net.xml and stop file. Furthermore, it can adapt a route-file so it matches the updated network.

Example call:

python tools/net/ <stopfile> -n <net-file> -r <route-file> -o <output-net-file> --stop-output <output-stop-file> --route-output <output-route-file> --stop-type busStop


A similar functionality is achieved by --split-output FILE which splits edges at the midpoint between stops.

Converts a geodetical rail network into an abstract (schematic) rail network. If the network is segmented (with, the resulting network will be a hybrid of multiple schematic pieces being oriented in a roughly geodetical manner

Example call:

python tools/net/ -n --stop-file input_additional.add.xml --region-file stations.taz.xml --output-prefix abstract

It is also possible to automatically segment the network:

python tools/net/ -n --stop-file input_additional.add.xml --split --output-prefix abstract

Further options#

  • --filter-regions: Only convert the given list of regions and delete everything else
  • --keep-all: When filtering regions, keep all other regions at their old geometry. This may be used to build region-specific patch files than can the combined to patch larger parts of the network**
  • --horizontal: The abstract network is aligned on the horizontal
  • --track-offset: Define the offset between parallel tracks in m (default 20)
  • --skip-building: Only create patch files but do not assemble the new network
  • --skip: creates a region file (taz) from the stop-file, optionally splits network edges to ensure that each edge belongs to a single station


If the network is large and not segmented or if the individual station segments are large, the conversion process can take a long time. The option --skip-large INT can be used to selective skip large regions (measured by the number of optimization constraints, reported via --verbose output).


If option --skip is used the original network may be split (under a new name) and the generated abstract network will have the same edges as the split net. The input stop-file will also be adapted for the split net (under a new name) but any traffic demand (route files) have to be adapted for the split network.