Intelligent transportation systems, coupling information, communication and sensor technologies, aim to improve traffic safety and energy efficiency, while reducing traffic congestion and air pollution. To meet the challenges of the 21st century in the field of road transport, simulation platforms are receiving increasing attention, in an attempt to advance intelligent transportation system (ITS) optimization. Although a plethora of simulation platforms for intelligent transportation systems exist, formalism have not yet been reported that ensure reliable data exchange among different ITS simulation platforms. This paper presents a conceptual model serving as a formal basis for designing ITS simulation platforms for roads based on building information modeling (BIM), which is a method mandated in many European countries when designing and building public infrastructure. In this paper, an extension of the current BIM standard, the Industry Foundation Classes (IFC) schema, is proposed, enabling standard-compliant, BIM-based simulation of intelligent transportation systems for roads. First, the conceptual model is presented, serving as a basis for the IFC schema extension. Then, the IFC schema extension is described and verified with the test software of the official IFC certification program. Next, an illustrative BIM-based simulation scenario is presented for validating the IFC schema extension. The paper concludes with a summary and an outlook on potential future research.