A navigation roadmap database with fusion interface of incremental local roadnet

A navigation roadmap database is designed based on spider-web roadmap model, which describes complex connectivities of roadnet with abstract spider-like nodes. Fast route-planning algorithm and navigation guidance functions can be well implemented on this roadmap database. A storage format is carefully designed therefor element replace and add on interfaces are reserved in the database with which incremental local net can be fused into the original roadmap. Thus Roadmap is updated with incremental data.