TRB Paper #03-3629 A Spatial-Temporal Object Database Approach to Dynamic Segmentation

Dynamic segmentation is viewed as one of the most important functions of GIS for transportation applications. Although the road network and associated events (e.g. pavement material, traffic volume and incidents) can be referenced to both space and time, the spatial and temporal dimensions has not been well integrated. This paper explores how to model space-varying, time-varying and space-time-varying events in dynamic segmentation using an object database approach that is in line with the Object Database Management Group (ODMG) standard. A mechanism, called parametric polymorphism, is utilized to lift conventional data types to spatial, temporal and spatialtemporal types for maintaining knowledge about events that could change spatially, temporally, and spatial-temporally along linear features. An associated object query language, called DS-OQL, has also been designed to support the formulation of spatial, temporal and spatialtemporal queries on the road and event information.