摘要: |
Sharing of digital road map databases within and among organizations is dependent on translating user requirements to a data model that supports linear and non-linear location referencing systems. This paper examines issues of creating such a data model with the intent of sharing digital road map databases, and suggests implementation choices that can accommodate a range of applications. The proposal is best characterized as a GIS-T enterprise data model suitable for organizations responsible for any and all modes of transportation; e.g., aviation, highways, public transit, and railways. The proposed data model may be sufficiently robust to support ITS map database interoperability by maintaining independence among the geographic datum, the events that occur on the transportation system, the geometry to represent the system cartographically, and the paths through the system. Sample physical database designs are provided to show how the model might be implemented. |