Route condition evaluation method and apparatus for navigation system
A method and apparatus for a navigation system evaluates an overall cost of each candidate route by incorporating traffic information such as traffic incident types and traffic flow speeds. An optimum route to the destination is determined by comparing the costs of two or more candidate routes and selecting a candidate route of the least cost. The method and apparatus determines relevancy and accuracy of the traffic information and adjusting the cost of the candidate route. When the traffic information on the candidate route shows a conflicting situation, the method and apparatus modifies the cost derived from the traffic information. When modifying the cost, the traffic speed information is prioritized over other type of traffic information.
1. A route condition evaluation method for a navigation system, comprising the following steps of:
creating candidate routes to a destination specified by a user based on a cost of each candidate route derived from map data;
receiving traffic information from a traffic information server;
identifying the traffic information associated with the candidate routes; and
evaluating an overall cost of each candidate route incorporating a cost derived from the traffic information on the candidate route to determine an optimum route to the destination;
wherein said cost derived from the traffic information will be modified when the traffic information on the candidate route shows a conflicting situation; and
wherein said step of evaluating the overall cost includes a step of increasing the cost of a candidate route when the traffic information shows a traffic incident on the candidate route that causes a slow traffic speed on the candidate route, and said traffic incident includes a traffic accident, stalled vehicle, police inspection, fire, lane closure, and construction.
2. A route condition evaluation method for a navigation system as defined claim 1 , further comprising a step of comparing the costs of two or more candidate routes and selecting a candidate route of least cost as the optimum route to the destination.
3. A route condition evaluation method for a navigation system as defined claim 1 , wherein, when said conflicting situation is caused by the traffic information which includes traffic incident type information and traffic speed information for the same candidate route, the traffic speed information is prioritized for obtaining the cost derived from the traffic information.
4. A route condition evaluation method for a navigation system as defined claim 1 , wherein, when said conflicting situation is caused because one candidate route shows traffic speed information while another candidate route lacks traffic speed information, a traffic speed for the another candidate route is created by decreasing a maximum allowable speed of the another candidate route by a predetermined ratio, thereby increasing the cost.
5. A route condition evaluation method for a navigation system as defined claim 1 , wherein, when said conflicting situation is caused because one candidate route shows traffic speed information while another candidate route lacks traffic speed information, a traffic speed for the one candidate route is increased by a predetermined ratio, thereby decreasing the cost.
6. A route condition evaluation method for a navigation system as defined claim 1 , wherein said cost of each candidate route derived from the map data includes a distance, time length, and fee of the route.
7. A route condition evaluation method for a navigation system as defined in claim 1 , wherein said step of receiving the traffic information includes a step of displaying a traffic incident icon and traffic speed data with respect to a map image of the candidate route.
8. A route condition evaluation method for a navigation system as defined in claim 1 , wherein said step of receiving the traffic information includes a step of communicating with the traffic information server through a wireless or wired communication device.
9. A route condition evaluation apparatus for a navigation system, comprising:
means for creating candidate routes to a destination specified by a user based on a cost of each candidate route derived from map data;
means for receiving traffic information from a traffic information server;
means for identifying the traffic information associated with the candidate routes; and
means for evaluating an overall cost of each candidate route incorporating a cost derived from the traffic information on the candidate route to determine an optimum route to the destination;
wherein said cost derived from the traffic information will be modified when the traffic information on the candidate route shows a conflicting situation; and
wherein said means for evaluating the overall cost includes means for increasing the cost of a candidate route when the traffic information shows a traffic incident on the candidate route that causes a slow traffic speed on the candidate route, and said traffic incident includes a traffic accident, stalled vehicle, police inspection, fire, lane closure, and construction.
10. A route condition evaluation apparatus for a navigation system as defined claim 9 , further comprising means for comparing the costs of two or more candidate routes and selecting a candidate route of least cost as the optimum route to the destination.
11. A route condition evaluation apparatus for a navigation system as defined claim 9 , wherein, when said conflicting situation is caused by the traffic information which includes traffic incident type information and traffic speed information for the same candidate route, the traffic speed information is prioritized for obtaining the cost derived from the traffic information.
12. A route condition evaluation apparatus for a navigation system as defined claim 9 , wherein, when said conflicting situation is caused because one candidate route shows traffic speed information while another candidate route lacks traffic speed information, a traffic speed for the another candidate route is created by decreasing a maximum allowable speed of the another candidate route by a predetermined ratio, thereby increasing the cost.
13. A route condition evaluation apparatus for a navigation system as defined claim 9 , wherein, when said conflicting situation is caused because one candidate route shows traffic speed information while another candidate route lacks traffic speed information, a traffic speed for the one candidate route is increased by a predetermined ratio, thereby decreasing the cost.
14. A route condition evaluation apparatus for a navigation system as defined claim 9 , wherein said cost of each candidate route derived from the map data includes a distance, time length, and fee of the route.
15. A route condition evaluation apparatus for a navigation system as defined in claim 9 , wherein said means for receiving the traffic information includes means for displaying a traffic incident icon and traffic speed data with respect to a map image of the candidate route.
16. A route condition evaluation apparatus for a navigation system as defined in claim 9 , wherein said means for receiving the traffic information includes means for communicating with the traffic information server through a wireless or wired communication device.