| Transportation agencies manage data that is primarily linearly referenced (i.e., using linear referencing methods such as milepost and stationing). However, with the advent of GPS and other spatial technologies, for applications such as incident management, these agencies are managing data that is referenced in two, three, and four (three spatial dimensions plus time) dimensions. The number and type of dimensional coordinate systems, i.e., Location Referencing Systems (LRS), vary across transportation agencies and often within organizations as well. Several transportation agencies, through recognition of the significance of spatially-referenced information to their operations, have identified the need for the comprehensive management of location referencing through a data model derived from a clear set of functional requirements. Providing the structures needed for spatio-temporal data management will allow transportation agencies to implement improved transportation information systems and advanced Geographic Information Systems for Transportation (GIS-T) technology.; This research represents the “next step” in the development of location referencing system data models in transportation by documenting, presenting, and illustrating a comprehensive data model that accommodates the elements necessary to use transportation-based multi-dimensional spatio-temporal data. These elements include multi-dimensional location referencing, error propagation, multi-scale representations, navigation, and temporal GIS. The Multi-Dimensional, Multi-Modal Transportation Location Referencing System (MDLRS) data model is developed from a set of stakeholder-driven functional requirements, each based on existing research. To facilitate interoperability of data sets, the MDLRS data model is formulated in the context of existing geo-spatial standards. To enable agencies to adopt the MDLRS data model or parts of it, implementation structures are provided. These implementation structures provide agencies the basics for creating procurement documents or requests for proposals (RFP). To validate the MDLRS, data model, a working prototype is developed and tested. Results from the working prototype are used to refine the MDLRS data model and implementation structures. |
