Software Architecture for a Transparent and Versatile Traffic Simulation

MATSim is a traffic simulation software package which can be customized and extended in the Java programming language using a set of interfaces. It recently acquired a plug-in system which was implemented using framework-assisted dependency injection, a pattern more typically used in enterprise rather than research software. We describe the extension points and the implementation of the plug-in system. The architecture makes it easier and safer to combine independently developed components to complex simulation models, compared to many ad-hoc solutions often found in research software.