BIM-GIS Integration Is Closer Than Ever: A Unified Road Model for IFC and CityGML Interoperability

Abstract

Building information modeling (BIM) and geographic information systems (GISs) are increasingly integrated to meet modern infrastructure demands. A key challenge is the lack of interoperability between the Industry Foundation Classes road model used in BIM and the CityGML transportation model used in GIS. This study presents the unified road model, a framework for bidirectional interoperability by aligning semantic definitions, geometric representations, and attribute mappings to preserve engineering and geospatial data. The unified road model combines volumetric data from the Industry Foundation Classes with CityGML’s multiple levels of detail and was validated through a signalized intersection and a roundabout in the Örebro–Karlskoga corridor in Sweden. Results show the unified road model connects data from both domains, maintaining attributes such as material properties, alignment geometry, and spatial relationships. This demonstrates its potential to enhance multidisciplinary workflows, reduce data loss, and improve BIM–GIS collaboration. The study recommends further research into automation, scalability, and smart city applications.