An approach to describe arbitrary transition curves in an IFC-based alignment product data model

Open standards for infrastructure based on Industry Foundation Classes (IFC) are mainly developed by the open INFRA initiative of the building Smart organization. Recently, several proposals for alignment models emerged with the development of the upcoming IFC 5 standard that, in particular, targets infrastructure projects such as roads, bridges and tunnel buildings. A common drawback of all of these proposals is their limited description of arbitrary transition curves. For instance, in all proposed alignment models, there are some missing types of transition curves or different parameters are suggested to describe a certain transition curve type. Designing a neutral data format that satisfies all stakeholders in an international context is, therefore, difficult. A novel approach to describe transition curves based on the Industry Foundation Classes Programming Language (IFCPL) is described and its integration into an IFC-based alignment model is shown to avoid these problems.