METHOD AND DEVICE FOR PREPARING DATA BASE, AND PROGRAM STORAGE MEDIUM, AND SPEED RESULT INFORMATION DISPLAYING DEVICE, AND TRAVELING TIME CALCULATING DEVICE, AND ROUTE RETRIEVING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a method for preparing a data base for offering the traffic information of roads including non-trunk roads. SOLUTION: This method is used for preparing a data base for managing the speed result information of vehicles traveling on roads in each mesh divided by a Voronoi diagram with primary intersections as nodes. This method comprises a process for obtaining traveling result information including vehicle positions and vehicle speeds, a process for obtaining the speed result information of vehicles traveling between nodes belonging to each mesh and nodes positioned near the nodes according to the obtained traveling result information, and for obtaining the speed result information in each specified direction of vehicles which do not travel between the nodes, and a process for preparing a data base for managing the speed result information of the vehicles traveling on trunk roads and the speed result information in each direction of the vehicles traveling on non-trunk roads corresponding to each mesh according to the obtained speed result information.