Traffic State Predicting Apparatus

• US 20080077316A1
• Filed: 08/09/2007
• Published: 03/27/2008
• Est. Priority Date: 09/27/2006
• Status: Active Grant

• Current Assignee: Clarion Co., Ltd. (Faurecia SA)
• Original Assignee: Xanavi Informatics Corporation (Hitachi, Ltd.)
• Inventors: Takahashi, Hirotaka, YAMANE, Kenichiro, Okude, Mariko
• Granted Patent: US 8,180,557 B2
• Time in Patent Office: Days
• US Class Current: 701/119
• CPC Class Codes: G01C 21/3694 Output thereof on a road map
• CPC Class Codes: G08G 1/0104 Measuring and analyzing of parameters relative to traffic conditions

Abstract

A traffic state predicting apparatus, which predicts congestion states of parts of a link based on limited information (the travel time for the link), comprises storage means that stores link data including a link length of each link forming part of a road on a map and parameters including, for each link, a smooth traffic speed indicting being smooth, a congested traffic speed indicating being congested, and a congestion reference position which is a reference position for a congested section; means that acquires a predicted travel time for the link; and congestion degree classified section calculating means that obtains sections classified according to their level of congestion in the link with use of the predicted travel time and the parameters.

Claims

1. A traffic state predicting apparatus comprising:

storage means that stores link data including a link length of each link forming part of a road on a map and parameters including, for each link, a smooth traffic speed indicating being smooth, a congested traffic speed indicating being congested, and a congestion reference position which is a reference position for a congested section;

means that acquires a predicted travel time for the link; and

congestion degree classified section calculating means that obtains sections classified according to their level of congestion in the link with use of the predicted travel time and the parameters.

2. The traffic state predicting apparatus according to claim 1, wherein the congestion degree classified section calculating means classifies sections of a link according to their level of congestion so that the sum of times for which to pass at travel speeds respectively through the sections is a travel time for the link and that the sum of the lengths of the sections is the link length of the link.

3. The traffic state predicting apparatus according to claim 2, wherein the congestion degree classified section calculating means takes the level of congestion for the entire link as being of smoothness if a congestion length is negative, and the level of congestion for the entire link as being of congestion if a smooth length is negative.

4. The traffic state predicting apparatus according to claim 2, wherein the parameters include a plurality of congestion reference positions for each link, and

wherein the congestion degree classified section calculating means selects one of the plurality of congestion reference positions which, together with a congestion length, defines a congested section whose length is within the link length of the link, and using the selected congestion reference position, obtains sections classified according to their level of congestion in the link.

5. A traffic state predicting apparatus comprising:

means that acquires traffic information including a travel time for each link forming part of a road on a map, sections classified according to their level of congestion in the link, congestion reference positions that are each a reference position for congestion, and a congestion length; and

parameter creating means that creates parameters to be used when obtaining sections classified according to their level of congestion in the links with use of the traffic information,

wherein the parameters include, for each link, a smooth traffic speed indicating being smooth, a congested traffic speed indicating being congested, and congestion reference positions which are each a reference position for a congested section.

6. The traffic state predicting apparatus according to claim 5, wherein the parameter creating means obtains respective frequencies of the congestion reference positions from the congestion reference positions of each link contained in the traffic information and makes a predetermined number of congestion reference positions that are highest in the frequency be included in the parameters.

7. The traffic state predicting apparatus according to claim 5, wherein the parameter creating means comprises:

travel speeds-for-each congestion degree calculating means that obtains travel speeds for each level of congestion for each link;

means that arranges the travel speeds for each level of congestion in ascending order or descending order and, for each level of congestion, acquires travel speeds located in predetermined percentiles of the total number of travel speeds;

congestion degree classified section calculating means that obtains sections classified according to their level of congestion in each link with use of each of the acquired travel speeds for each level of congestion and the travel time of the link; and

means that obtains an evaluated value from matching between the obtained sections and sections classified according to their level of congestion contained in the traffic information,

wherein the travel speed for each level of congestion that gives the highest evaluated value is made to be included in the parameters.

8. The traffic state predicting apparatus according to claim 7, wherein the congestion degree classified section calculating means classifies sections of a link according to their level of congestion so that the sum of times for which to pass at travel speeds respectively through the sections is a travel time for the link and that the sum of the lengths of the sections is the link length of the link.

9. The traffic state predicting apparatus according to claim 7, further comprising:

means that acquires a representative travel speed of a link,

wherein the travel speeds-for-each congestion degree calculating means takes the representative travel speed as the congested traffic speed if the congestion length is at or greater than a predetermined proportion of the link length, and the representative travel speed as the smooth traffic speed if the congestion length is smaller than the predetermined proportion of the link length.

10. The traffic state predicting apparatus according to claim 5, further comprising:

means that acquires a predicted travel time for a link; and

congestion degree classified section calculating means that obtains sections classified according to their level of congestion in the link with use of the predicted travel time and the parameters.

11. A traffic state predicting method for a traffic state predicting apparatus which comprises:

storage means that stores link data including a link length of each link forming part of a road on a map and parameters including, for each link, a smooth traffic speed indicating being smooth, a congested traffic speed indicating being congested, and a congestion reference position which is a reference position for a congested section,

the predicting method comprising the steps of;

acquiring a predicted travel time for the link; and

obtaining sections classified according to their level of congestion in the link with use of the predicted travel time and the parameters.