Traffic information providing system and method for generating traffic information

• US 8,239,124 B2
• Filed: 06/12/2008
• Issued: 08/07/2012
• 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
• Primary Examiner(s): BEAUCHAINE, MARK J
• Application Number:
  US12/138,174
• Publication Number:
  US 20080312811A1
• Time in Patent Office: 1,517 Days
• Field of Search: 701/118, 701/119, 701/117, 340/933, 340/934, 340/936
• 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 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; and

further comprising

a speed processing step for determining a travel speed of a specific link by extracting and 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;

wherein in said speed processing step, if an amount of the extracted traffic information data in the target area before the size is increased or after the size is increased is sufficient, a predetermined percentile speed is selected from a distribution of speed values of the extracted traffic information data 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, if the amount of the extracted traffic information data in the target data after the size is increased is insufficient, an average speed of the distribution of the speed values relating to the specific link located in the target area is set to be the value of the tentative speed on the specific link.

2. 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; and

further comprising

a speed compensation step, wherein a tentative speed value determined from a distribution of speed values extracted from said traffic information data is subjected to at least one correction function;

wherein said correction function is a monotonically increasing function with values between a lower speed limit and an upper speed limit.

3. 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; and

further comprising

a speed compensation step, wherein a tentative speed value determined from a distribution of speed values extracted from said traffic information data is subjected to at least one correction function;

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.

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; and

further comprising

a speed compensation step, wherein a tentative speed value determined from a distribution of speed values extracted from said traffic information data is subjected to at least one correction function;

wherein said speed compensation step comprises the step of subsequently applying at least a first correction function and a second correction function to the tentative speed value.

5. 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; and

further comprising

a speed compensation step, wherein a tentative speed value determined from a distribution of speed values extracted from said traffic information data is subjected to at least one correction function; and

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 an unexpected result.

6. The method according to claim 5, 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 area by multiplying the speed values with the ratio.

7. A traffic information providing device that generates traffic information for a car navigation system, comprising:

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

a data volume check unit that determines whether a volume of the traffic information data is sufficient for performing a statistical estimate for the travel time, determines whether the volume of traffic information data relating to links located in a target area is sufficient, and adapts a size of the target area depending on the amount of available traffic information data; and

a speed compensation unit, in which a tentative speed value determined from a distribution of speed values extracted from the traffic information data is subjected to at least one correction function;

wherein the correction function is a monotonically increasing function with values between a lower speed limit and an upper speed limit.

8. A traffic information providing device that generates traffic information for a car navigation system, comprising:

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

a data volume check unit that determines whether a volume of the traffic information data is sufficient for performing a statistical estimate for the travel time, determines whether the volume of traffic information data relating to links located in a target area is sufficient, and adapts a size of the target area depending on the amount of available traffic information data; and

a speed compensation unit, in which a tentative speed value determined from a distribution of speed values extracted from the traffic information data is subjected to at least one correction function;

wherein, in the speed compensation unit, a characteristic value for a road density within an area comprising the specific link is calculated and the correction function is determined depending on the characteristic value.

9. A traffic information providing device that generates traffic information for a car navigation system, comprising:

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

a data volume check unit that determines whether a volume of the traffic information data is sufficient for performing a statistical estimate for the travel time, determines whether the volume of traffic information data relating to links located in a target area is sufficient, and adapts a size of the target area depending on the amount of available traffic information data; and

a speed compensation unit, in which a tentative speed value determined from a distribution of speed values extracted from the traffic information data is subjected to at least one correction function;

wherein the speed compensation unit subsequently applies at least a first correction function and a second correction function to the tentative speed value.

10. A traffic information providing device that generates traffic information for a car navigation system, comprising:

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

a data volume check unit that determines whether a volume of the traffic information data is sufficient for performing a statistical estimate for the travel time, determines whether the volume of traffic information data relating to links located in a target area is sufficient, and adapts a size of the target area depending on the amount of available traffic information data;

a speed compensation unit, in which a tentative speed value determined from a distribution of speed values extracted from the traffic information data is subjected to at least one correction function; and

a speed processing unit, in which average speeds of different road types within the same area are compared and the average speeds are adjusted if the comparison yields an unexpected result.

11. The traffic information providing device of claim 10, wherein the speed processing unit determines 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 area by multiplying the speed values with the ratio.