Software patterns and architectural decisions for a NextGeneration Traffic Management System in the TANGENT project

This paper introduces the TANGENT project and how it is exploring Dynamic Management of Multimodal Traffic in four European cities. It focuses on how specific software patterns and architectural decisions are contributing to the success in creating and trialling a Simulation powered Next-Generation Traffic Management System. It starts by exploring the motivation behind a TANGENT API where a REST API coexists with a Message Queue Broker and how they synergize to cover the different needs of distinct data producers and consumers within and around the TANGENT project. It then explores a generic approach for the different pieces of the TANGENT API. How incoming data handling from the message queue service is implemented generically in the TANGENT API, how the REST API is implemented with this same approach and how the OpenAPI documentation of the REST API is produced. Highlighting the central role of the JSON Schemas and meta-data stored in TANGENT Schema catalogue and how it is simple to add new data sources with this approach as opposed to custom handling the individual data sources.