An Evaluation of IFC-CityGML Unidirectional Conversion for Road and Transportation Models

Abstract. The integration of Building Information Modeling (BIM) and Geographic Information Systems (GIS) is increasingly critical for infrastructure planning, asset management, and smart city applications. While prior efforts have largely focused on buildings, the need for semantically rich, interoperable models for roads and transportation networks is becoming more prominent. This paper investigates the potential for unidirectional conversion between IFC 4.3-based road models and the Transportation model of CityGML 3.0. Through manual schema matching, the study classifies correspondences into full, partial, or no match categories and assesses the potential for semantic and geometric translation between the two domains. Findings reveal that while basic spatial and geometric entities can be mapped with partial fidelity, significant semantic details such as alignment geometry, layered road structures, and road furniture remain unmapped. The paper concludes by recommending the development of a unified road ontology or mediation layer to support lossless integration. These insights contribute to ongoing efforts in GeoBIM interoperability, such as those led by buildingSMART International and the OGC's CityGML working groups.