The existing road-network models based on the 2D link-node of roadway centrelines have inhibited lane-oriented network flow analysis and multi-dimensional inventory management in complicated 3D urban environments. This paper proposes a hierarchical lane-oriented 3D road-network model (HL-3DRNM), with a unified modelling language (UML) diagram. HL-3DRNM is a non-planar topological model with the support of a 3D lane ribbon cartographic display, which is characterized by: (1) multiple topological and cartographic representations and various abstraction levels (street, road segment, carriageway and lane); and (2) referenced multi-dimensional road information (point, line, area and volume) at lane level. HL-3DRNM provides solid mathematical foundations for a more detailed inventory management, effective network analysis and realistic navigation in the increasingly complicated 3D urban transportation systems.