Abstract: There is provided a method and a device for accurately estimating traffic information of a link having no traffic information even if different types of roads are mixed. The device finds a parameter characterizing a damping curve of a quantity of change of relative speed based on stored traffic information for links on a city center side on a minimum-time cost route connecting the city center and suburbs, finds a quantity of change of relative speed of the link having no observed traffic information and estimates its traffic information based on the damping curve. The device also calculates a ratio of quantities of change of relative speed of two links whose road types change as a speed change similarity ratio and estimates traffic information of the link of a second road type from known traffic information of the link of a first road type by using that ratio.

Abstract: There is provided a method and a device for accurately estimating traffic information of a link having no traffic information even if different types of roads are mixed. The device finds a parameter characterizing a damping curve of a quantity of change of relative speed based on stored traffic information for links on a city center side on a minimum-time cost route connecting the city center and suburbs, finds a quantity of change of relative speed of the link having no observed traffic information and estimates its traffic information based on the damping curve. The device also calculates a ratio of quantities of change of relative speed of two links whose road types change as a speed change similarity ratio and estimates traffic information of the link of a second road type from known traffic information of the link of a first road type by using that ratio.

Abstract: There is provided a method and a device for accurately estimating traffic information of a link having no traffic information even if different types of roads are mixed. The device finds a parameter characterizing a damping curve of a quantity of change of relative speed based on stored traffic information for links on a city center side on a minimum-time cost route connecting the city center and suburbs, finds a quantity of change of relative speed of the link having no observed traffic information and estimates its traffic information based on the damping curve. The device also calculates a ratio of quantities of change of relative speed of two links whose road types change as a speed change similarity ratio and estimates traffic information of the link of a second road type from known traffic information of the link of a first road type by using that ratio.

Abstract: An information center (5000) for collecting traffic information stores in its memory device the latest map data. Then, it is determined through a terminal device (5030) whether or not history information has been recorded in a data recording medium (800) mounted in a navigation device (1000), and when it is determined that the history information has been recorded, the map data in the data recording medium are updated to the latest map data. The data recording medium (800) is removable from the navigation device (1000). Statistical traffic information may be updated along with the updating of the map data. Further, when history information is directly uploaded to the information center, an identifier is attached to the uploaded information.

Abstract: A navigation device that calculates an expected travel time or an expected arrival time for each retrieved route, using link costs predetermined for calculation of expected travel times regardless of search conditions. As the link costs for the calculation of expected travel times, are used link travel times obtained by statistically processing traffic information collected in the past, for example.

Abstract: A position coordinate based route transmitted from a server is reconstructed as a route of link numbers or node numbers in map data of navigation apparatus without error. A route guidance server searches a route from a start point to end point designated by a navigation apparatus; selects all or a part of nodes included in the searched route as route nodes; sets complementary points to the respective selected route nodes on the route and at a distance longer than a predetermined distance from the respective route nodes; and transmits information including coordinate information on the route nodes and complementary points as route information to the navigation apparatus. Then, based on the coordinate information on the route nodes and complementary points transmitted from the server, the navigation apparatus identifies the route nodes and road links connecting the route nodes by identification numbers in map data the navigation apparatus it self has.

Abstract: A server device 1 included in the route-search system 7 comprises a guided-navigation-route-search section 130 for searching a route starting from a departure point and reaching a destination; and a preparatory-route-search section 140 for searching a preparatory route in view of a possible deviation of the vehicle from a navigation route. The server device 1 transmits information on the navigation route and the preparatory route to the navigation device 2. When detecting the deviation of the vehicle, the navigation device 2 selects one of preparatory routes having nodes closest to the current position of the vehicle. The navigation device 2 searches a supplementary route connecting the current position of the vehicle to the nodes, and combines the preparatory route with the supplementary route to create a new route for continuing navigating the vehicle to the destination.

Abstract: Route search is performed considering the fact that traffic conditions differ according to lane even for the same road. A navigation device performs route search, using link costs (link travel times) classified by lane. For example, the navigation device searches for a route having the lowest total cost to the destination, using link data that determine cost for each lane of a component link of a road on a map. A cost of a lane on which a vehicle runs to move to a next link, being the cost of any lane of the link, is used as a cost of a link on a route.

Abstract: A navigation device displays predicted traffic information downloaded from a server device and statistical traffic information stored in a storage unit, on the same screen. Both information items may be displayed in such a manner that at least a part of them is overlaid (a superimposed display). The predicted traffic information may be superimposed on the statistical traffic information. When traffic information of the same time band of the same object (link, mesh area) exists in both the information items, one thereof may be selected to be displayed.

Abstract: A recommended route is searched by the use of traffic information collected in the past. A map/statistical traffic data storage device 3 stores map data including link data of respective links constituting roads on a map, and statistical data including travel time or moving speeds of the respective links determined by statistical values of traffic information collected in the past. Said statistical data is classified every condition of collection of traffic information. A navigation device searches a recommended route from a departure position to a destination by using the map data stored in the map/statistical traffic data storage device and statistical data corresponding to a day type and a weather type which constitute conditions of search, out of statistical data stored in the map/statistical traffic data storage device 3.

Abstract: Predicted traffic information of a plurality of time bands is downloaded once for a mesh area. Moreover, time band range of the predicted traffic information to be downloaded is increased as distance from current position to the mesh area increases. Furthermore, the time band range is increased for the morning and the evening. Moreover, as difference between the current time and departure time becomes larger, the time band range is increased.

Abstract: When receiving a traffic information providing request, a traffic information providing apparatus analyzes which area's traffic information is requested based on the received request information. Traffic information of road links located in the requested area is read from the traffic information, and it is determined whether the road links' traffic information is similar or not. Similar links configure a link group, and traffic information corresponding to the link group is created. Traffic information of the configured link group is delivered to an in-vehicle information apparatus.

Abstract: A navigation device displays predicted traffic information downloaded from a server device and statistical traffic information stored in a storage unit, on the same screen. Both information items may be displayed in such a manner that at least a part of them is overlaid (a superimposed display). The predicted traffic information may be superimposed on the statistical traffic information. When traffic information of the same time band of the same object (link, mesh area) exists in both the information items, one thereof may be selected to be displayed.

Abstract: There is provided a method and a device for accurately estimating traffic information of a link having no traffic information even if different types of roads are mixed. The device finds a parameter characterizing a damping curve of a quantity of change of relative speed based on stored traffic information for links on a city center side on a minimum-time cost route connecting the city center and suburbs, finds a quantity of change of relative speed of the link having no observed traffic information and estimates its traffic information based on the damping curve. The device also calculates a ratio of quantities of change of relative speed of two links whose road types change as a speed change similarity ratio and estimates traffic information of the link of a second road type from known traffic information of the link of a first road type by using that ratio.

Abstract: The navigation device of the present invention has a storage device which stores map data including link data of respective links constituting roads on a map, and statistical data including travel time (moving speed) which is determined by statistical values of traffic information collected in the past, with respect to each of the links. Then, the navigation device uses for each departure time candidate, the map data and the statistical data of collection conditions corresponding to the statuses upon passing each of the route constituting links which constitute the route, so as to obtain the travel time for each of the route constituting links. Thereafter, the travel times of respective route constituting links thus obtained are summed up, and the travel time between the departure position and the destination is obtained.

Abstract: An information center (5000) for collecting traffic information stores in its memory device the latest map data. Then, it is determined through a terminal device (5030) whether or not history information has been recorded in a data recording medium (800) mounted in a navigation device (1000), and when it is determined that the history information has been recorded, the map data in the data recording medium are updated to the latest map data. The data recording medium (800) is removable from the navigation device (1000). Statistical traffic information may be updated along with the updating of the map data. Further, when history information is directly uploaded to the information center, an identifier is attached to the uploaded information.

Abstract: A technique which enables a navigation system mounted on a vehicle or the like to be connected with an information providing device by utilizing a short range base station. In cases where a recommended route passes through a communication spot, which is an area enabled for communication by the short range base station, the navigation system is connected with the information providing device through the base station, after moving as far as the communication spot, and in cases where the recommended route does not pass through the communication spot, the system is connected with the information providing device through a public network by a communication terminal.

Abstract: A navigation device that calculates an expected travel time or an expected arrival time for each retrieved route, using link costs predetermined for calculation of expected travel times regardless of search conditions. As the link costs for the calculation of expected travel times, are used link travel times obtained by statistically processing traffic information collected in the past, for example.

Abstract: A technique which enables a navigation system mounted on a vehicle or the like to be connected with an information providing device by utilizing a short range base station. In cases where a recommended route passes through a communication spot, which is an area enabled for communication by the short range base station, the navigation system is connected with the information providing device through the base station, after moving as far as the communication spot, and in cases where the recommended route does not pass through the communication spot, the system is connected with the information providing device through a public network by a communication terminal.

Abstract: Route search is performed considering the fact that traffic conditions differ according to lane even for the same road. A navigation device performs route search, using link costs (link travel times) classified by lane. For example, the navigation device searches for a route having the lowest total cost to the destination, using link data that determine cost for each lane of a component link of a road on a map. A cost of a lane on which a vehicle runs to move to a next link, being the cost of any lane of the link, is used as a cost of a link on a route.