Semantic and Geometric Aspects of Integrating Road Networks

A prototype of a Geographic Database Integrator is under investigation and development. One of the long term goals of the Geographic Database Integrator is to reduce the need for operator intervention in update operations between objects in different databases. This paper focuses on the research related to road network elements from two independently surveyed and maintained topographic databases, one at large scale and one at mid-scale. Central to the issue of update propagation is certainty of equivalence of different road object representations. Therefore, precise definitions of road segment and road junction are important. In both the large and mid-scale geographic data sets, the roads are area features, although the whole may be considered as one linear road network. In order to find the junctions and road segments, the constrained Delaunay triangulation is applied. Using these well defined elements, a strategy for finding equivalent or corresponding road network elements has been developed. This forms the basis for processing and propagating updates in the road network from one database to the other database.