KR101004440B1 - Congestion information display apparatus and center apparatus - Google Patents

Abstract

The on-vehicle navigation device 1 receives a plurality of continuous congestion information from the center device 2, and when the connection angle of the connection point connecting the plurality of continuous congestion information satisfies a predetermined condition, The congestion information is connected and displayed so as to be one piece of congestion information following the road link shape of the road map data. By displaying the traffic jam information in an appropriate display mode as described above, valuable traffic jam information is supplied to the driver.

Navigation, Traffic Information, Connection Points, Connection Angles

Description

Identity information display and center device {CONGESTION INFORMATION DISPLAY APPARATUS AND CENTER APPARATUS}

According to the present invention, the center apparatus generates, and transmits, the traffic jam information to a traffic jam information display device having a predetermined length indicating a traffic jam level based on the probe data (current position, orientation, vehicle speed) received from the vehicle, and displaying the traffic jam information. A center information display apparatus and a center apparatus that can be used in a system configured to superimpose and display congestion information received from a center apparatus on a road link of road map data.

Conventionally, the center apparatus generates the congestion information (congestion line) of a predetermined length indicating the congestion level based on the probe data (current position, orientation, vehicle speed) received from the onboard navigation apparatus, and transmits it to the onboard navigation apparatus. A system is provided in which a vehicle-mounted navigation device is configured to superimpose and display congestion information received from a center device on a road link of road map data (see, for example, Patent Documents 1 and 2).

[Patent Document 1] Japanese Patent Application Laid-Open No. 7-239997

[Patent Document 2] Japanese Patent Application Laid-Open No. 2001-194170

Therefore, when congestion information is displayed superimposed on the road link of a curved road, since a plurality of continuous congestion information is displayed by the display mode of the broken line, there exists a problem which is inferior in the aspect of visibility. In particular, the greater the curvature of a road, for example, a place called JC (junction) where the highways join and branch, or a so-called IC (interchange) where the highway and the general road join and branch. The problem as mentioned above is remarkable.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and one aspect of the object is to provide a congestion information display apparatus capable of supplying the driver with valuable congestion information by displaying the congestion information in an appropriate display mode, and transmitting the congestion information in an appropriate transmission mode. The present invention provides a center device capable of supplying valuable driver information to a driver from a user information display device.

According to the traffic jam information display apparatus described in this invention, when a traffic jam information receiving means receives the traffic jam information of predetermined length which shows the traffic jam level from a center apparatus, a control means reads road map data from the road map data storage means, The received congestion information is superimposed on the road link of the road map data and displayed on the display means. Here, the control means receives a plurality of continuous stagnation information from the center apparatus, and when the connection angle of the connection point which connects this continuous plurality of stagnation information satisfies a predetermined condition, a plurality of continuous stagnation information is received. The display means connects to display one piece of congestion information that follows the shape of the road link of the road map data read from the road map data storage means.

Accordingly, it is determined that the connection angle of the connection point for connecting the plurality of continuous pieces of congestion information is, for example, the first predetermined angle or less or the second predetermined angle or more, and the road overlapping the plurality of continuous pieces of congestion information is a curved road. When the plurality of continuous pieces of congestion information is displayed in a broken line display mode, the plurality of pieces of congestion information can be displayed in a display mode of a curve following the road link shape of the road map data. It can increase visibility and provide drivers with valuable traffic information.

Further, according to the center apparatus described in the present invention, when the control means receives the probe data from the vehicle by the probe data receiving means, the control means has a predetermined length of congestion indicating the level of congestion based on the probe data received by the probe data receiving means. Information is generated and transmitted from the congestion information transmitting means to the congestion information display apparatus. Here, when the connection angle of the connection point which connects the generated continuous congestion information satisfy | fills a predetermined condition, the control means road of the road map data which read the plurality of continuous congestion information from the road map data storage means. It connects so as to become one piece of congestion information following the link shape, and transmits it to the piece of information display device from the piece of congestion information transmitting means.

Accordingly, it is determined that the connection angle of the connection point for connecting the plurality of continuous pieces of congestion information is, for example, the first predetermined angle or less or the second predetermined angle or more, and the road overlapping the plurality of continuous pieces of congestion information is a curved road. In this case, the plurality of consecutive pieces of congestion information are connected and transmitted so as to be one piece of congestion information that follows the road link shape of the road map data, so that the congestion information display device performs the same as described in claim 1 above. A plurality of pieces of congestion information can be displayed in a curved display mode on the road link shape of the road map data, thereby improving visibility and supplying valuable congestion information to the driver.

According to the present invention as described above, a congestion information display apparatus capable of supplying valuable congestion information to a driver by displaying congestion information in an appropriate display mode, and displaying congestion information by transmitting the congestion information in an appropriate transmission mode It is possible to provide a center device capable of supplying the driver with valuable congestion information from the device.

EMBODIMENT OF THE INVENTION Hereinafter, one Embodiment which applied this invention to the onboard navigation apparatus is demonstrated with reference to drawings. FIG. 1 shows the configuration of an on-vehicle navigation device by a combination of functional blocks, and FIG. 2 schematically shows the overall configuration of the system.

The on-board navigation device 1 (the congestion information display device according to the present invention) mounted on the vehicle and the center device 2 provided in the traffic information center are configured to be able to communicate via a mobile communication network. The on-vehicle navigation device 1 and the center device 2 have a relationship of N (unspecified number) to one, and the center device 2 can communicate with the unspecified number of on-vehicle navigation device 1 through a mobile communication network. It is composed.

The vehicle-mounted navigation device 1 includes a control unit 3 (control means of the traffic jam information display device according to the present invention), a position detector 4, a road map data input device 5, an operation switch group 6, a communication device ( 7) (congestion information receiving means referred to in the present invention), external memory 8, display device 9 (display means referred to in the present invention), voice controller 10, voice recognition device 11, and remote control sensor 12 ) Is configured.

The control unit 3 has a CPU, a RAM, a ROM, and an I / O bus, is composed of known microcomputers, and controls the operation of the entire apparatus by executing a control program. The position detector 4 comprises a G sensor 4a, a gyroscope 4b, a distance sensor 4c, and a GPS receiver 4d, each of which has a detection error that is different in nature from each other. The control unit 3 complements the detection signals input from each of these components and detects (specifies) the current position. In this case, if the position detector 4 can detect the current position with the required detection accuracy, it is not necessary to include all these components, and the steering sensor or each wheel for detecting the steering angle of the steering. A wheel sensor or the like for detecting the rotation of the wheel may be combined.

The road map data input device 5 is equipped with a recording medium 13 (road map data storage means according to the present invention) made of, for example, a DVD-ROM, and the road map data recorded on the recording medium 13 ( Road type, road shape, node information, etc.), beacon data, map matching data, and the like. The recording medium 13 may be a CD-ROM, a memory card, or an HDD. The operation switch group 6 is constituted by a mechanical switch disposed around the display device 9 or a touch switch formed on the display device 9, and is operated by a passenger including a driver (for example, a menu). Display selection, destination setting, route search, route guidance start, display screen change, volume adjustment, etc.) are detected and output to the control unit 3.

The communication device 7 communicates with the center device 2 via a mobile communication network. The external memory 8 is constituted by a mass storage device such as an HDD, and stores a large amount of data, data to be retained even when the power is turned off. The display device 9 is configured of, for example, a color liquid crystal display, and displays various display screens such as a menu display selection screen, or displays a current position figure, a driving trajectory, or the like indicating a current position on a road link of road map data. Overlap or display. In addition, the display device 9 may be composed of an organic EL, a plasma display, or the like.

The voice controller 10 controls the voice recognition device 11 and simultaneously outputs, for example, voice guidance of route guidance from the speaker 14. The speech recognition apparatus 11 recognizes the speech input by the microphone 15 according to a speech recognition algorithm. The remote control sensor 12 outputs an operation signal received from the operation remote control 16 to the control unit 3.

In addition, the controller 3 compares the road map data acquisition unit for acquiring road map data and the road map data obtained by comparing the current position with the road map data acquisition unit for each function, and map matching specifying a road link at which the current location exists. A route search unit for searching a route from a specific current position to a destination set by the passenger, a point required for route guidance based on a route searched by the route search unit and location data of intersections included in the road map data. A route guide section for calculating and guiding the route, a map around the current position, a drawing section of the highway, an enlarged map near the intersection, and the like.

In addition, the control unit 3 periodically transmits probe data having the current position, azimuth, and vehicle speed as one unit from the communication device 7 to the center device 2 via the mobile communication network, and at the same time, from the center device 2. When the transmitted congestion information (congestion line) is received by the communication device 7, the received congestion information is superimposed and displayed on the road link of the road map data read out from the recording medium 13. In addition, the vehicle in which the on-board navigation apparatus 1 comprised in this way is mounted may not be the vehicle in which the use is specifically limited.

The center device 2 includes a control unit 17 (control means of the center device according to the present invention) and a probe data receiving unit 18 (probe data according to the present invention) for receiving probe data transmitted from the on-vehicle navigation device 1. A receiving means), a congestion information transmitting unit 19 for transmitting congestion information (congestion information transmitting means according to the present invention), and a road map database 20 for storing road map data (road map data storage means according to the present invention). And a congestion information database 21 for storing congestion information. The control unit 17 has a CPU, RAM, ROM, and I / O bus, and is composed of known microcomputers, and controls the operation of the entire apparatus by executing a control program.

In this case, when the control unit 17 receives the probe data transmitted from the in-vehicle navigation device 1 by the probe data receiving unit 18, the control unit 17 extracts the current position and azimuth from the received probe data, and extracts the extracted current position. And road map data corresponding to the bearing are read from the road map database 20, and map-matches the current position to a road link of the road map data read from the road map database 20. FIG. The control unit 17 also extracts the vehicle speed from the probe data and generates congestion information for the road link that map-matched the current position according to the extracted vehicle speed.

Specifically, when the vehicle speed extracted from the probe data is "less than 10 km per hour", traffic jam information specifying the congestion level of the road link as "congestion" indicating high traffic volume is generated, and the vehicle speed is "less than 20 km per hour". If it is, the traffic congestion information which specifies the congestion level of the said road link as the "congestion" which shows the traffic volume is medium is generated, and if the vehicle speed is "20 km or more per hour," Congestion information identified by "empty road". Each time the controller 17 generates congestion information in this manner, the controller 17 writes the correspondence between the generated congestion information and the road link into the congestion information database 21 to update the congestion information database 21. At the same time, the latest congestion information is transmitted from the congestion information transmitting unit 19 to the on-vehicle navigation device 1.

In the on-vehicle navigation device 1, when the control unit 3 receives the congestion information transmitted from the center device 2 by the communication device 7, the road of the road map data overlapping the received congestion information. The link is read from the recording medium 13, and the received congestion information is superimposed on the road link of the corresponding road map data to be displayed on the display device 9. In this case, the control part 3 displays the congestion information received from the center apparatus 2 by changing a display aspect (for example, display color) according to a congestion level.

Specifically, when the congestion level of the congestion information received from the center apparatus 2 is "congestion", the control unit 3 displays the congestion information in red and the congestion level of the congestion information received from the center apparatus 2. If it is "congestion", the congestion information is displayed in yellow, and if the congestion level of the congestion information received from the center apparatus 2 is "freeway", the congestion information is displayed in blue. That is, the driver can confirm the magnitude (delay level) of the congestion level by confirming the display color of the displayed congestion information.

Next, the operation of the above-described configuration will be described with reference to FIGS. 3 to 6.

In the on-vehicle navigation device 1, the control unit 3 determines whether or not the communication device 7 has received the traffic jam information transmitted from the center device 2 (step S1), and the center device 2. If it is determined that the congestion information transmitted from the communication device 7 has been received by the communication device 7 (YES in step S1), it is determined whether there is a portion in which the received congestion information continues (step S2). Next, when the control part 3 determines that there exists a part which continues congestion information (YES in step S2), the connection angle of the connection point which connects this continuous multiple congestion information is below a 1st predetermined angle, or It is determined whether or not it is equal to or greater than the second predetermined angle (step S3).

Here, the connection angle of a connection point is an index which shows the curve degree of the road which overlaps a plurality of continuous congestion information, as shown in FIG. 4, The control part 3 has the connection angle R as a 1st predetermined angle. If it is in the range exceeding (for example, 150 degrees) and less than a 2nd predetermined angle (for example, 210 degrees), it is determined that the road which overlaps a plurality of congestion informations is a straight road, and a connection angle is 1st If the angle is less than or equal to the predetermined angle, the road overlapping the plurality of pieces of congestion information is determined to be a curved road that is bent to the left in the advancing direction. If the connection angle is greater than or equal to the second predetermined angle, the road overlaps the plurality of pieces of congestion information. Is determined to be a curved road that curves to the right from the direction of travel. In addition, the 1st predetermined angle and the 2nd predetermined angle mentioned here may be a fixed value preset, or may be a variable value which a user etc. can freely set.

When the control part 3 determines that the connection angle of the connection point which connects a plurality of continuous stagnation information is below 1st predetermined angle or above 2nd predetermined angle (YES in step S3), the connection angle is 1st predetermined | prescribed. It is determined whether the connection points satisfying the condition which is less than or equal to the angle or more than the second predetermined angle are continuous, and whether the plurality of consecutive pieces of congestion information to be connected are more than a predetermined number (step S4). The predetermined number here may be a fixed value which is set in advance, or may be a variable value that can be freely set by a user or the like. Then, when the control unit 3 determines that the plurality of continuous pieces of congestion information to be connected is less than a predetermined number (not a predetermined number or more) (NO in step S4), the control piece 3 stores the plurality of pieces of congestion information continuously. Connection is made so that one piece of congestion information follows the road link shape of the road map data read out from (13) (step S5).

On the other hand, when the control part 3 determines that the plurality of continuous pieces of congestion information to be connected is more than a predetermined number (YES in step S4), the control pieces 3 are arranged so that the plurality of pieces of consecutive pieces of congestion information to be connected is less than the predetermined number. The road link shape of the road map data obtained by dividing (step S6), reading the corresponding road map data from the recording medium 13, and reading a plurality of contiguous pieces of congestion information from the recording medium 13. Connection is made so as to have one piece of congestion information following (step S5).

Then, the control unit 3 specifies the congestion level to be displayed based on each congestion level of the plurality of congestion informations (step S7), and the road link of the road map data connecting the plurality of congestion informations successively. One piece of congestion information following the shape is displayed on the display device 9 at this specific level of congestion (step S8).

Specifically, a case in which the predetermined number, which is a criterion for determining whether to divide a plurality of consecutive pieces of congestion information, is set to "4" will be described as an example. The control unit 3 is as shown in FIG. Similarly, if two pieces of congestion information a1 and a2 whose congestion level is "congestion" satisfy the condition that the connection angle of the connection point is less than the first predetermined angle or more than the second predetermined angle, it should be displayed. One congestion that specifies "congestion" common to two congestion information a1 and a2 as congestion level, and follows the road link shape of road map data connecting the two consecutive congestion information a1 and a2. The information b1 is displayed on the display device 9 at the congestion level of "congestion".

In addition, as shown in FIG.5 (b), the control part 3 has two pieces of congestion information a1 of congestion level "congestion" and congestion information a2 of congestion level "congestion". When the connection angle of the connection point satisfies a condition that is equal to or less than the first predetermined angle or more than the second predetermined angle, the connection is congested with the longer stagnation information a1 as the stagnation level to be displayed. "Congestion" level is specified by specifying the level of priority, and one piece of congestion information b1 following the road link shape of the road map data which connects the plurality of consecutive pieces of congestion information a1 and a2. Is displayed on the display device 9.

In addition, as shown in Fig. 6A, the control unit 3 includes six pieces of stagnant information a11 to a16 having a stagnation level of "stagnant", and the connection angles of all the connection points thereof are equal to or less than the first predetermined angle. Alternatively, if the connection is made while satisfying a condition that is equal to or greater than the second predetermined angle, the six pieces of congestion information are divided into three pieces of congestion information, which are common to the three pieces of congestion information a11 to a13 as the congestion level to be displayed in the first half. In addition to specifying the "congestion", the "congestion" common to the three congestion information a14 to a16 is specified as the congestion level to be displayed in the latter part, and the three consecutive congestion information (a11 to the first half) are specified. While displaying one piece of information b11 following the road link shape of the road map data to which a13 is connected, the display device 9 at the level of congestion, three contiguous pieces of the latter part of the piece are displayed. Road map day which connected information (a14-a16) The one traffic congestion information (b12) to follow the road link shape to congestion level of "congested", it is displayed on the display device 9.

In addition, as shown in FIG.6 (b), the control part 3 has three pieces of congestion information (a11, a12, a15) whose congestion level is "congestion", and three pieces of congestion information whose congestion level is "congestion." If (a13, a14, a16) is connected while satisfying the condition that the connection angles of all the connection points are less than the first predetermined angle or more than the second predetermined angle, six pieces of information are divided by three pieces of information, As the level of congestion to be displayed in the first half parts a11 to a13, the congestion level of the longer congestion information a11 and a12 is given priority to specify "congestion" and the second part a14. As the level of congestion to be displayed by ˜a16), “congestion” is specified by giving priority to the level of congestion information (a14, a16) of the longest sum total of the length of the congestion information, and three consecutive pieces of congestion information of the first half portion thereof. Following the road link shape of the road map data connected (a11 to a13) Road link of road map data which displays one piece of congestion information b11 at the congestion level of "congestion" and connects three consecutive pieces of congestion information a14 to a16 in the latter part. One piece of congestion information b12 following the shape of is displayed on the display device 9 at the level of congestion. In FIG. 6, the case where six pieces of congestion information is divided into three pieces of congestion information has been described, but six pieces of information may be divided into four pieces of information and two pieces of information.

Accordingly, in the above-described vehicle-mounted navigation device 1, when a plurality of pieces of continuous traffic information received from the center device 2 are connected to display one piece of traffic information following the road link shape of the road map data. Although the above description has been made, in the center apparatus 2, when generating congestion information based on probe data received from the on-vehicle navigation apparatus 1, a plurality of consecutive congestion information is connected to the road link of the road map data. One piece of congestion information following the shape may be generated, and one piece of congestion information following the road link shape of the generated road map data may be transmitted to the on-vehicle navigation device 1.

That is, in the center apparatus 2, when the control unit 17 receives the probe data transmitted from the in-vehicle navigation device 1 by the probe data receiving unit 18, the congestion information is based on the received probe data. And the road link shape of the road map data which reads the plurality of pieces of congestion information from the road map database 20 when the connection angle of the connection point for connecting the plurality of pieces of congestion information that has been generated satisfies a predetermined condition. It may be connected so as to be one piece of congestion information to be followed, and transmitted from the congestion information transmitting unit 19 to the on-vehicle navigation device 1.

As described above, according to the present embodiment, in the on-vehicle navigation device 1, a plurality of continuous traffic jam information is received from the center device 2, and the plurality of traffic jam information is stored in the road map data. Since it is configured to connect and display one piece of congestion information following the road link shape, it is different from the conventional method of displaying a plurality of pieces of congestion information in the form of a broken line. It can be displayed in the display mode of the curve following the road link shape, and the visibility can be improved and valuable congestion information can be supplied to a driver.

If the plurality of continuous pieces of congestion information to be connected is more than a predetermined number, the predetermined plurality of pieces of contiguous pieces of congestion information are divided and divided so that the plurality of pieces of contiguous pieces of congestion information to be connected is less than a predetermined number. Since a plurality of consecutive pieces of congestion information is connected and displayed so as to be one piece of congestion information following the road link shape of the road map data, one piece of congestion information is displayed in the entire curved road in a section where the curved road continues. Rather than displaying, a plurality of pieces of congestion information can be displayed by dividing the curved road by a certain section, thereby further improving visibility.

Further, the plurality of pieces of continuous congestion information of the predetermined number or more are divided so that the number of connections is equal, so that one piece of congestion information that follows the road link shape of the road map data is divided into a plurality of pieces of contiguous pieces of congestion information. Since it is configured to connect and display, when displaying a plurality of pieces of congestion information by dividing the curved road into a certain section, the number of connections can be divided so that the number of pieces of congestion can be displayed in equal length, so that the visibility is further increased. It can increase.

In addition, when connecting plural pieces of congestion information having different congestion levels, the total sum of lengths of congestion information having the same congestion level is calculated for each congestion level, and the plurality of pieces of congestion information follows the road link shape of the road map data. In the case of connecting and displaying one piece of congestion information, the piece of congestion information is displayed at a congestion level having a maximum sum of lengths. Can be displayed at a high level of congestion, so that highly reliable congestion information can be supplied to the driver.

This invention is not limited only to embodiment mentioned above, It can change or expand as follows.

The predetermined number as a criterion for determining whether to divide a plurality of consecutive pieces of congestion information may be other than "4".

When connecting a plurality of congestion information having different congestion levels, the sum of the lengths of the congestion information having the same congestion level is calculated, and the congestion level having the maximum sum of the lengths of one piece of congestion information connected to the plurality of congestion informations is maximum. Is not limited to displaying priority information, but one piece of congestion information connected to a plurality of pieces of congestion information may be preferentially displayed.

1 illustrates an embodiment of the present invention, which is a functional block diagram of an onboard navigation device.

2 is a diagram illustrating an overall configuration of a system.

3 is a flowchart.

4 is a diagram illustrating a connection angle of a plurality of consecutive stagnation information.

FIG. 5 is a diagram illustrating a form in which a plurality of pieces of congestion information are connected.

6 is a view corresponding to FIG. 5.

Claims (8)

Congestion information receiving means for receiving congestion information of a predetermined length indicating a congestion level from the center apparatus and road map data storage means for storing road map data, and congestion received by the congestion information receiving means. A congestion information display apparatus comprising control means 3 that can be displayed on display means by superimposing information on road links of road map data read out from the road map data storage means, The control means reads out the plurality of pieces of congestion information from the road map data storage means when the connection angle of the connection point for connecting the plurality of pieces of congestion information received by the pieces of congestion information satisfies a predetermined condition. Connected to be one piece of congestion information following the road link shape of the road map data, and displayed on the display means; When the plurality of continuous pieces of congestion information to be connected is more than a predetermined number, the control means divides and groups the plurality of pieces or more of contiguous pieces of congestion information so that the plurality of pieces of contiguous pieces of congestion information to be connected is less than a predetermined number. And connect each group of a plurality of divided pieces of congestion information less than a predetermined number so as to become one piece of congestion information following the road link shape of the road map data read out from the road map data storage means and displayed on the display means. Letting Identity information display device. delete The method of claim 1, The control means divides the plurality of consecutive pieces of congestion information into a predetermined number or more so that the plurality of contiguous pieces of congestion information to be connected is less than a predetermined number and the number of connections is equal, and the plurality of pieces of contiguous numbers less than the divided number of pieces are divided. Each group of the congestion information is connected so as to be one piece of congestion information following on the road link of the road map data read from the road map data storage means and displayed on the display means. Identity information display device. The method according to any one of claims 1 to 3, When the plurality of pieces of congestion information having different levels of congestion are connected, the control means calculates the total sum of lengths of pieces of congestion information having the same level of congestion for each level of congestion, and stores the plurality of pieces of congestion information in the road map data storage means. When the display means connects one piece of congestion information following the road link shape of the road map data read out from the display means and displays the piece of congestion information on the display means at a level of congestion with a maximum total length. Identity information display device. Probe data receiving means for receiving probe data from a vehicle, road map data storage means for storing road map data, and congestion information of a predetermined length indicating a congestion level based on probe data received by the probe data receiving means. A center apparatus having control means for generating and transmitting from the congestion information transmitting means to the congestion information display apparatus, The control means, when the connection angle of the connection point for connecting the generated plurality of pieces of congestion information satisfies a predetermined condition, the road link of the road map data read the plurality of pieces of congestion information from the road map data storage means Connected to be one piece of congestion information following the shape and transmitted from the piece information transmitting means to the piece information display device, When the plurality of continuous pieces of congestion information to be connected is more than a predetermined number, the control means divides and groups the plurality of pieces or more of contiguous pieces of congestion information so that the plurality of pieces of contiguous pieces of congestion information to be connected is less than a predetermined number. And connecting each group of a plurality of divided plurality of pieces of congestion information smaller than the predetermined number so as to be one piece of information following the road link shape of the road map data read out from the road map data storing means. To send from the identity information display device Center unit. delete The method of claim 5, The control means divides the plurality of consecutive pieces of congestion information into a predetermined number or more so that the plurality of contiguous pieces of congestion information to be connected is less than a predetermined number and the number of connections is equal, and the plurality of pieces of contiguous numbers less than the divided number of pieces are divided. Each group of congestion information is connected so as to be one piece of congestion information following the road link shape of the road map data read out from the road map data storing means and transmitted from the congestion information transmitting means to the congestion information display device. Center unit. The method according to any one of claims 5 to 7, When the plurality of pieces of congestion information having different levels of congestion are connected, the control means calculates the total sum of lengths of pieces of congestion information having the same level of congestion for each level of congestion, and stores the plurality of pieces of congestion information in the road map data storage means. A level of congestion at which the total sum of lengths is maximum when connecting one piece of congestion information following the road link shape of the road map data read out from the congestion information transmitting means to the congestion information display device. Transmitting from the congestion information transmitting means to the congestion information display device Center unit.

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