TRAFFIC INFORMATION PROVIDING SYSTEM AND METHOD FOR GENERATING TRAFFIC INFORMATION

• US 20080312811A1
• Filed: 06/12/2008
• Published: 12/18/2008
• Est. Priority Date: 06/15/2007
• Status: Active Grant

• Current Assignee: Xanavi Informatics Corporation (Hitachi, Ltd.)
• Original Assignee: Xanavi Informatics Corporation (Hitachi, Ltd.)
• Inventors: YAMANE, Kenichiro
• Granted Patent: US 8,239,124 B2
• Time in Patent Office: Days
• US Class Current: 701/118
• CPC Class Codes: G08G 1/0104 Measuring and analyzing of parameters relative to traffic conditions

Abstract

The invention relates to a method for generating traffic information to be used in a car navigation system, comprising the steps of acquiring traffic information data including information relating to a travel time of links making up a road on a map and for acquiring map data relating to the link, the map data comprising at least information on a road type of the link and checking if a volume of the traffic information data available in is sufficient for performing a statistical estimate for the travel time. In order to enhance the traffic information generated, it is proposed to use the steps of checking if the volume of traffic information data relating to links located in a target area is sufficient and adapting a size of the target area depending on the amount of available traffic information data.

Claims

1. A traffic information providing system for creating traffic information to be used in a car navigation system, comprising:

a data getting unit for acquiring traffic information data including information relating to a travel time of links making up a road on a map and for acquiring map data relating to the link, said map data comprising at least information on a road type of the link; and

a data volume check unit for checking if a volume of the traffic information data available in a target area is sufficient for performing a statistical estimate for the travel time,

wherein said data volume check unit is configured to check the volume of traffic information data relating to links located in a target area and to adapt a size of the target area depending on the amount of available traffic information data.

2. The traffic information providing system according to claim 1, wherein said data volume check unit is configured to increase the size of the target area if a volume of traffic information data relating to links located in a previously chosen target are is insufficient.

3. The traffic information providing system according to claim 1, further comprising a speed processing unit for determining a travel speed of a specific link by evaluating the traffic information data relating to links of the same or similar road type and being located in the same target area as the specific link.

4. A method for generating traffic information to be used in a car navigation system, comprising the steps of:

acquiring traffic information data including information relating to a travel time of links making up a road on a map and for acquiring map data relating to the link, said map data comprising at least information on a road type of the link;

checking if a volume of the traffic information data available in is sufficient for performing a statistical estimate for the travel time;

checking if the volume of traffic information data relating to links located in a target area is sufficient; and

adapting a size of the target area depending on the amount of available traffic information data.

5. The method according to claim 4, wherein in the step of checking the volume of data the size of the target area is increased if a volume of traffic information data relating to links located in a previously chosen target are is insufficient.

6. The method according to claim 4, further comprising a speed processing step for determining a travel speed of a specific link by evaluating the traffic information data relating to links of the same or similar road type and being located in the same target area as the specific link.

7. The method according to claim 6, wherein in said speed processing step, a predetermined percentile speed is selected from a distribution of speed values extracted from said traffic information data and relating to links of the same or similar road type and being located in the same target area as the specific link and the value of a tentative speed on the specific link is set to be equal to the value of said predetermined percentile speed.

8. The method according to claim 4, further comprising a speed compensation step, wherein a tentative speed value determined from a distribution of speed values extracted from said traffic information data by is subjected to at least one correction function.

9. The method according to claim 8, wherein said correction function is a monotonically increasing function with values between a lower speed limit and an upper speed limit.

10. The method according to claim 8, wherein in said speed compensation step, a characteristic value for a road density within an area comprising the specific link is calculated and the correction function is determined depending on said characteristic value.

11. The method according to claim 8, wherein said speed compensation step comprises the subsequent application of at least a first correction function and a second correction function to the tentative speed value.

12. The method according to claim 8, further comprising a speed adjustment step, wherein average speeds of different road types within the same area are compared and wherein the average speeds are adjusted if the comparison yields to an unexpected result.

13. The method according to claim 12, wherein said speed adjustment step comprises the step of determining a ratio of the adjusted average speed and the original average speed for each road type and the step of adjusting the speed values for each link of the same road type in the same are by multiplying it with the thus determined ratio.

14. A data Storage Device comprising a database of traffic information generated according to the method of claim 4.

15. A car Navigation System comprising a data storage device according to claim 14 and a processor for performing a route search based on the traffic information stored on the data storage device.

16. A method for generating traffic information to be used in a car navigation system, comprising the steps of:

acquiring traffic information data including information relating to a travel time of links making up a road on a map and for acquiring map data relating to the link, said map data comprising at least information on a road type of the link;

checking if a volume of the traffic information data available in is sufficient for performing a statistical estimate for the travel time;

checking if the volume of traffic information data relating to links located in a target area is sufficient and;

adapting a size of the target area depending on the amount of available traffic information data,

wherein in the step of checking the volume of data the size of the target area is increased if a volume of traffic information data relating to links located in a previously chosen target are is insufficient.

17. A traffic information providing system for creating traffic information to be used in a car navigation system, comprising:

a data getting unit for acquiring traffic information data including information relating to a travel time of links making up a road on a map and for acquiring map data relating to the link, said map data comprising at least information on a road type of the link; and

a data volume check unit for checking if a volume of the traffic information data available in a target area is sufficient for performing a statistical estimate for the travel time,

wherein said data volume check unit is configured to check the volume of traffic information data relating to links located in a target area and to adapt a size of the target area depending on the amount of available traffic information data, wherein said data volume check unit is further configured to increase the size of the target area if a volume of traffic information data relating to links located in a previously chosen target are is insufficient.