Emerging data management needs of road administrations stress the need for data integration, when various isolated systems are updated and maintained in parallel. Since road objects can be static or dynamic, referenced to one, two, three or four dimensions, the traditional 2-D road data models are insufficient to support data integration. In order to comprehend the user requirements, a multi-dimensional conceptual data model was introduced considering a criteria list compiled based on previous studies conducted on implemented systems. The diverging approach from the traditional planar (2-D) road data models is multidimensionality, involving 3-D geometry and time. The presented model involves multi-dimensional location referencing, multiscale representation, history of objects and metadata. A significant deficiency of traditional road data models, being non-integrated I-D, 2-D and 3-D road data, was eliminated by means of the newly developed methodology, Dynamic Reference Transformation, for transformations. The designed concepts are applied to parts of real road databases using the integrated approach and results are discussed. By managing to express the user requirements in multiple dimensions, the usage of emerging spatial technologies (e.g. airborne laser scanning and digital photogrammetric cameras) in transportation applications is expected to increase. (C) 2004 Elsevier B.V. All rights reserved.