Traffic-jam state calculation systems, methods, and programs

• US 8,428,858 B2
• Filed: 03/11/2008
• Issued: 04/23/2013
• Est. Priority Date: 03/19/2007
• Status: Expired due to Fees

• Current Assignee: Aisin AW Company Limited (Aisin Corp.)
• Original Assignee: Aisin AW Company Limited (Aisin Corp.)
• Inventors: Ishikawa, Hiroki, Igawa, Junichiro
• Primary Examiner(s): Black, Thomas
• Assistant Examiner(s): LI, CE LI
• Application Number:
  US12/073,868
• Publication Number:
  US 20080234922A1
• Time in Patent Office: 1,869 Days
• Field of Search: 701/1, 701/117, 701/118, 701/119
• US Class Current: 701/119
• CPC Class Codes: G08G 1/0104 Measuring and analyzing of parameters relative to traffic conditions

Abstract

Systems, methods, and programs obtain probe information, the probe information comprising an average speed of probe cars traveling on each of a plurality of links in a predetermined area. The systems, methods, and programs detect, for each of the plurality of links, a first degree of a traffic jam corresponding to the link for each of a plurality of different thresholds by comparing the average speed with each of the thresholds. The systems, methods, and programs obtain traffic-jam information concerning the plurality of links, the obtained traffic information comprising a second degree of the traffic jam corresponding to each of the plurality of links. The systems, methods, and programs compare, for each of the plurality of links, the second degree of the traffic jam with the first degree of the traffic jam for each of the thresholds. The systems, methods, and programs select, for the predetermined area, a threshold from the plurality of thresholds for which the first degree of the traffic jam most matches the second degree of the traffic jam and utilize the selected threshold to determine a severity of the traffic jam for each of the plurality of links.

Claims

1. A traffic jam state calculation system comprising:

a controller that;

obtains probe information, the probe information comprising an average speed of probe cars traveling on each of a plurality of links in a predetermined area;

compares the average speed of each of the plurality of links with each of a plurality of thresholds, each of the plurality of thresholds having a different value;

based on the comparison, detects, for each of the plurality of links, a first degree of a traffic jam corresponding to the link for each of the plurality of different thresholds;

obtains traffic jam information concerning the plurality of links, the obtained traffic information comprising a second degree of the traffic jam corresponding to each of the plurality of links;

compares, for each of the plurality of links, the second degree of the traffic jam with the first degree of the traffic jam for each of the thresholds;

selects, for the predetermined area, a threshold from the plurality of thresholds for which the first degree of the traffic jam most matches the second degree of the traffic jam, the threshold usable to differentiate a degree of the traffic jam in the predetermined area; and

utilizes the selected threshold to determine a severity of the traffic jam for each of the plurality of links.

2. The traffic jam state calculation system according to claim 1, wherein the controller:

determines the severity of the traffic jam for each of the plurality of links by comparing the average speed of probe cars traveling on each link with the selected threshold.

3. The traffic jam state calculation system according to claim 1, wherein the controller:

selects a plurality of thresholds for the predetermined area, each of the selected thresholds respectively corresponding to each of a plurality of road attributes.

4. The traffic jam state calculation system according to claim 1, wherein the obtained traffic jam information is information that is based on the sensing of a vehicle by a stationary sensor located on a road.

5. The traffic jam state calculation system according to claim 1 wherein the predetermined area is at least one of:

one of a plurality of meshes; and

one of a plurality of prefectures.

6. The traffic jam state calculation system according to claim 1, wherein the controller:

applies, as a threshold of an area within a prefecture for which no traffic jam information can be obtained, an average of thresholds of areas in the prefecture in which traffic jam information was obtained.

7. The traffic jam state calculation system according to claim 1, wherein the controller:

applies, as a threshold of an area within a prefecture for which no traffic-jam information can be obtained, a median of thresholds of areas in the prefecture in which traffic jam information was obtained.

8. The traffic jam state calculation system according to claim 1, wherein the controller:

applies, as a threshold of an area within a prefecture in which no traffic jam information can be obtained, a threshold of an area adjacent to the area for which no traffic-jam information can be obtained.

9. The traffic jam state calculation system according to claim 1, further comprising:

a communication apparatus that transmits the determined severity of the traffic jam for each of the plurality of links to a navigation system in a vehicle.

10. The traffic jam state calculation system according to claim 1, further comprising:

a communication apparatus that receives the probe information from a navigation system in a vehicle.