Lane-Changing Model

This short document describes how a new lane-changing model can be added to SUMO.


A Lane-Changing Model is at least an order of magnitude more complicated than a car-following model (judging by the amount of code alone).

It is recommended to learn about the architecture of the model from the Publication SUMO's Lane-Changing Model.

The lane-changing model's class#

The best thing is to start with an already existing model. Models are located in <SUMO_HOME>/src/microsim/lcmodels and new added models should reside here, too. Copy both MSLCM_LC2013.h and MSLCM_LC2013.cpp and rename them. The name should be "MSLCModel_<YOUR_MODELS_NAME>".


lane-changing model implementations are located in <SUMO_HOME>/src/microsim/lcmodels.


A lane-changing class' name should start with "MSLCModel_".

Now, open both files and rename all occurrences of MSLCM_LC2013 into your class' name.

Add the files to the <SUMO_HOME>/src/microsim/lcmodels/CMakeLists.txt.

Loading into simulation#

We now add the XML-elements which allow us to define and parse the model's parameter. Extend the list of known elements "SUMOXMLDefinitions::tags" located in <SUMO_HOME>/src/utils/xml/SUMOXMLDefinitions.cpp. In SUMOXMLDefinitions::laneChangeModelValues add new values i.e. { "LCXYZ", LaneChangeModel::LCXYZ } (but not as the last element in the array) and add the corresponding element to enum class LaneChangeModel.

Lane-changing models are instantiated in MSAbstractLaneChangeModel::build located in <SUMO_HOME>/src/microsim/lcmodels/MSAbstractLaneChangeModel.cpp. You'll find a switch, here where you have to put the call to your model's constructor into.

You may note that all the paramters for the model are loaded within the constructur rather than being passed as arguments.

However, you need to register any novel parameters in SUMOVehicleParserHelper::parseLCParams located in <SUMO_HOME>/src/utils/vehicle/SUMOVehicleParserHelper.cpp.

For further interaction, you also have to adapt the "id" of the model in the new model's .h class:

virtual int getModelID() const {
 return LaneChangeModel::LCXYZ;

Using Custom Parameters via TraCI#

A LaneChangeModel can override the functions getParameter and setParameter inherited from MSAbstractLaneChangeModel. Any calls to 'traci.vehicle.setParameter' and 'traci.vehicle.getParameter' where the key starts with "laneChangeModel." will then be forwarded to these methods (without the prefix). The call traci.vehicle.setParameter(vehID, "laneChangeModel.XYZ", "42") will be mapped onto the call MSAbstractLaneChangeModel::setParameter("XYZ" , "42") which is called on the current laneChangeModel of the vehicle.

XML Validation#

Sumo performs xml validation. If you add new XML elements or attributes you either need to adapt the XML schema files in <SUMO_HOME>/data/xsd or add the option

--xml-validation never