Processing device, processing method, and computer program

Abstract

This processing device is provided with a control unit that performs information processing according to input data entered by a user, wherein the input data includes a node extraction condition for extracting, from among a plurality of nodes included in map data, a plurality of intersection nodes that are to be evaluated to determine whether or not the intersection node is a target intersection that requires an adjustment of a constant of a traffic signal controller, and an index condition for specifying a traffic index used for the evaluation from among a plurality of traffic indices, and wherein the information processing includes: processing for extracting one or more intersection nodes that meet the node extraction condition; processing for calculating, for each extracted intersection node or a route connecting to the intersection node, a traffic index specified by the index condition, on the basis of time-series data of traffic information; processing for extracting one or more target intersections from among the extracted one or more intersection nodes on the basis of the calculated traffic index; and processing for outputting the extracted one or more target intersections to a display unit.

Description

Processing device, processing method, and computer program

[0001] This application claims priority from Japanese Patent Application No. 2024-111962, filed on July 11, 2024, the disclosure of which is incorporated herein by reference in its entirety.

[0002] Patent Document 1 discloses a technique for displaying to a user traffic signal controllers that require adjustment of signal control parameters (hereinafter referred to as "constant adjustment") in order to alleviate congestion.

[0003] Traffic signal control methods are classified into centralized control (remote control), in which a central device at a traffic control center controls traffic signal controllers at multiple intersections, and individual control (point control), in which traffic signal controllers operate independently. In the centralized control method, the central device generates signal control commands as appropriate according to traffic conditions and sends these commands to the traffic signal controllers in an attempt to alleviate congestion.

[0004] In contrast, adjusting the constants of a single-control traffic signal controller requires a worker to go to the site and manually operate the traffic signal controller. Therefore, a technology is needed to display to users such as workers the target intersections that contain traffic signal controllers that require constant adjustment.

[0005] In Patent Document 1, time-series data of traffic information such as link average speeds is generated based on probe information acquired from vehicles, and the time-series data is stored in a database. The information processing device in Patent Document 1 determines that links entering an intersection where traffic signals are controlled using a single control method, and that links whose link average speeds are below a predetermined threshold, are congested oncoming routes. If there is a bias in the length of congestion between multiple oncoming routes entering the same intersection, the device detects a "one-way congestion" at the intersection and extracts the intersection as a target intersection requiring constant adjustment. Finally, the information processing device outputs the target intersection to a display unit.

[0006] International Publication No. 2022 / 123832

[0007] The processing device of the present disclosure includes a control unit that executes information processing in accordance with input data entered by a user, the input data including node extraction conditions for extracting, from a plurality of nodes included in map data, a plurality of intersection nodes that are to be evaluated as to whether or not the intersections are target intersections that require constant adjustment of traffic signal controllers, and index conditions that specify a traffic index to be used for the evaluation from a plurality of traffic indexes, and the information processing includes a first process of extracting one or more intersection nodes that satisfy the node extraction conditions, a second process of calculating, based on time-series data of traffic information, the traffic index specified by the index condition for the intersection node extracted in the first process or a route connecting to the intersection node, a third process of extracting one or more target intersections from the plurality of intersection nodes extracted in the first process based on the traffic index calculated in the second process, and a fourth process of outputting the one or more target intersections extracted in the third process to a display unit.

[0008] The embodiments of the present disclosure may be achieved by an apparatus, a system, a method, an integrated circuit, a computer program, or a computer-readable non-transitory recording medium, or any combination thereof. The recording medium may be either volatile or non-volatile. The apparatus may be composed of multiple individual devices. When composed of multiple individual devices, they may be arranged in a single housing or may be arranged separately in two or more separate housings.

[0009] FIG. 1 is a schematic configuration diagram of an information processing device according to an embodiment. FIG. 2 is a diagram illustrating an example of an input screen for specifying first extraction conditions. FIG. 3 is a diagram illustrating another example of the input screen. FIG. 4 is a diagram illustrating an example of an input screen for specifying third and fourth extraction conditions. FIG. 5 is an explanatory diagram illustrating an example of time-series data of traffic information. FIG. 6 is a flowchart illustrating an example of information processing content. FIG. 7 is a flowchart illustrating details of intersection detection processing. FIG. 8 is an example of an intersection node detected in the intersection detection processing. FIG. 9 is an example of a merging point node excluded from candidate nodes in the intersection detection processing. FIG. 10 is a flowchart illustrating details of entrance road detection processing. FIG. 11 is an explanatory diagram illustrating an example of an upstream link detected by the entrance road detection processing. FIG. 12 is an explanatory diagram illustrating an example of traffic congestion imbalance. FIG. 13 is an explanatory diagram illustrating an example of a congestion ahead. FIG. 14 is an explanatory diagram illustrating an example of a bottleneck. FIG. 15 is an explanatory diagram illustrating an example of a right-turn overflow. FIG. 16 is an explanatory diagram illustrating an example of a display screen. FIG. 17 is an explanatory diagram illustrating an example of a display screen. FIG. 18 is an explanatory diagram illustrating an example of a display screen.

[0010] In Patent Document 1, "one-way congestion" at an intersection is detected based on the "congestion length" of the incoming road, and a target intersection that requires constant adjustment is selected from multiple intersections using the presence or absence of one-way congestion as a selection criterion. However, traffic phenomena (hereinafter referred to as "events") that require constant adjustment are not limited to "one-way congestion" but are diverse. The traffic indicators used to detect these events are also diverse and not limited to "congestion length."

[0011] Therefore, the technology of Patent Document 1 has the problem that while it is possible to extract intersections where a ``one-sided congestion'' that can be detected based on the ``congestion length'' is occurring among the target intersections where the user originally wants to adjust the constants, it may not be able to extract other target intersections.

[0012] In view of such problems, the present disclosure aims to more comprehensively present to the user target intersections where constant adjustment of traffic signal controllers is required.

[0013] According to the present disclosure, it is possible to more comprehensively present to the user target intersections that require constant adjustment of traffic signal controllers.

[0014] The following provides an outline of embodiments of the present disclosure.

[0015] (1) A processing device according to the present disclosure includes a control unit that executes information processing in response to input data entered by a user, the input data including node extraction conditions for extracting, from among multiple nodes included in map data, multiple intersection nodes that are to be evaluated as to whether or not the intersections are target intersections requiring constant adjustment of traffic signal controllers, and index conditions that specify a traffic index to be used for the evaluation from among multiple traffic indexes, and the information processing includes a first process of extracting one or more intersection nodes that meet the node extraction conditions, a second process of calculating, based on time-series data of traffic information, the traffic index specified by the index condition for the intersection node extracted in the first process or a route connecting to the intersection node, a third process of extracting one or more target intersections from among the multiple intersection nodes extracted in the first process, based on the traffic index calculated in the second process, and a fourth process of outputting the one or more target intersections extracted in the third process to a display unit.

[0016] Since the user can specify the desired traffic index from among multiple traffic indexes as input data, the target intersections that require constant adjustment can be presented to the user more comprehensively than if the traffic index were limited to one from the beginning.

[0017] (2) In the processing device of (1) above, the index condition may include congestion length, delay time, and traffic volume as at least one of the plurality of traffic indexes.

[0018] By using these traffic indices, when suggesting to the user target intersections that require constant adjustment, it is possible to display suggestions that are more in line with the user's wishes.

[0019] (3) In the processing device of (1) or (2) above, when a plurality of traffic indicators are specified as the indicator condition, the control unit may output the plurality of traffic indicators for one target intersection extracted in the third process to the display unit.

[0020] Since multiple traffic indicators can be displayed for one target intersection, the user can grasp the traffic conditions at the target intersection in more detail.

[0021] (4) In the processing device of (1) to (3) above, the input data may further include an event condition that specifies an event to be used to extract the target intersection from among a plurality of events that require the constant adjustment, and the control unit may, in the third process, extract the target intersection where the event specified in the event condition was detected from among the intersection nodes extracted in the first process, based on the traffic index calculated in the second process.

[0022] This makes it possible to display proposals that more precisely meet the user's wishes when proposing to the user target intersections that require constant adjustment.

[0023] (5) In the processing device of (4) above, the event condition may include at least one of the following as the plurality of events: congestion imbalance, one-way congestion, multiple stops at traffic lights, congestion ahead, bottleneck, reduced flow rate, right-turn overflow, and left-turn overflow.

[0024] This makes it possible to display to the user the target intersections where an event has been detected that may alleviate congestion by adjusting the constants of the traffic signal controllers at the target intersections.

[0025] (6) In the processing device of (4) or (5) above, when a plurality of events are specified as the event condition, the control unit may be capable of transitioning in the fourth process between a state in which the target intersection at which a plurality of events are detected overlapping is output to the display unit, and a state in which the target intersection at which any of the plurality of events is detected is output to the display unit.

[0026] This allows the user to transition between a state in which they grasp target intersections that are particularly in need of constant adjustment (target intersections where multiple overlapping events have been detected) and a state in which they grasp multiple events comprehensively, making it easier for them to grasp the traffic conditions at each target intersection.

[0027] (7) In the processing device of (1) to (6) above, the node extraction conditions include at least one of a designated area, which is a geographical range designated by the user, an upper limit value for the number of placements designated by the user, and a designated class, which represents a road scale designated by the user, and the control unit, in the first processing, if the node extraction conditions include the designated area, extracts nodes included in the designated area; if the node extraction conditions include the upper limit value, extracts nodes in which the number of placements of signal lamp marks in the map data is equal to or less than the upper limit value; and if the node extraction conditions include the designated class, extracts nodes connected to a route in the map data whose road class is the designated class.

[0028] This allows nodes to be extracted based on conditions such as geographical range.

[0029] (8) In the processing device of (1) to (7) above, the input data may further include a time condition that limits a time range within the time series data that is to be evaluated as to whether the intersection is the target intersection, and the control unit may calculate the traffic index in the second processing based on data from the time series data that meets the time condition.

[0030] This allows the time series data to be limited by a time range.

[0031] (9) The method according to this embodiment is a processing method performed by the processing apparatuses (1) to (8) described above. Therefore, the processing method according to this embodiment has the same effects as the processing apparatuses (1) to (8) described above.

[0032] (10) The computer program according to this embodiment is a computer program for causing a computer to function as the processing device described above in (1) to (8). Therefore, the computer program according to this embodiment has the same effects as the processing device described above in (1) to (8).

[0033] <Details of Embodiments of the Present Disclosure> Hereinafter, details of embodiments of the present disclosure will be described with reference to the drawings. At least some of the embodiments described below may be combined in any manner.

[0034] [Configuration Example of Information Processing Device] FIG. 1 is a schematic configuration diagram of an information processing device 1 according to this embodiment. The information processing device 1 is, for example, a single personal computer (PC) or a server computer. The information processing device 1 may be configured with multiple computers. In this case, these multiple computers may be installed in the same facility or may be scattered across multiple locations that are separated from one another. When the information processing device 1 is configured with multiple computers, these computers cooperate via a network such as a public communication network to achieve the functions of a single information processing device 1.

[0035] The information processing device 1 extracts intersections where traffic events (hereinafter referred to as "events") requiring constant adjustment have occurred as target intersections based on one or more traffic indices selected from a plurality of traffic indices, and displays the target intersections to the user. The user can, for example, specify the traffic indices to be evaluated and the events to be detected, and the information processing device 1 extracts the target intersections based on the instructions. Because multiple traffic indices are prepared for detecting events, target intersections requiring constant adjustment can be presented to the user more comprehensively.

[0036] The information processing device 1 includes a housing 10 and electronic devices housed in the housing 10. The electronic devices include a control unit (information processing unit) 11, a storage unit 12, and a communication unit 13. An operation unit 14, a display unit 15, and a reading unit 16 are connected to the housing 10 of the information processing device 1.

[0037] The control unit 11 is mounted on a motherboard inside the housing 10, and the storage unit 12 and communication unit 13 are attached to dedicated connectors provided on the motherboard. The operation unit 14, display unit 15, and reading unit 16 are each connected to a predetermined connection port provided on the housing 10, and exchange predetermined information with the control unit 11 via a backplane or a bus. The control unit 11 controls the operations of the storage unit 12, communication unit 13, operation unit 14, display unit 15, and reading unit 16.

[0038] The control unit 11 is configured as an arithmetic processing device including a CPU (Central Processing Unit) and a main memory. The main memory of the control unit 11 is a volatile memory, a RAM (Random Access Memory). The CPU of the control unit 11 reads a computer program (software) 121 installed in the storage unit 12 into the main memory and performs various information processing in accordance with the read computer program 121.

[0039] The storage unit 12 is an auxiliary storage device including a nonvolatile memory such as a hard disk drive (HDD) and a solid state drive (SSD). The storage unit 12 may also include a flash read-only memory (ROM), a universal serial bus (USB) memory, or an SD card. The storage unit 12 stores a computer program 121, various parameters, and map data 18 in the nonvolatile memory.

[0040] The communication unit 13 is a communication card (for example, a LAN card) that performs Ethernet (registered trademark) communication with an external device. The communication unit 13 is connected to a gateway that is connected to the Internet via a predetermined communication cable such as a LAN cable or a wireless LAN.

[0041] The operation unit 14 is an input device including a keyboard and a pointing device such as a mouse. The operation unit 14 may include a touch panel device that allows a user to input operations by touching the screen of the display unit 15 with a finger or the tip of a pen. A user such as a traffic engineer can send a predetermined command to the control unit 11 by inputting operations such as keyboard input, mouse clicks, or touch operations.

[0042] The display unit 15 is a display device such as a liquid crystal monitor or an organic EL (Electro Luminescence) panel. The display unit 15 displays various GUI (Graphical User Interface) screens in accordance with operation commands from the control unit 11. The various GUI screens include a screen for receiving operation input from the operation unit 14 and a screen containing a map.

[0043] The reading unit 16 is a reading device that reads information from a recording medium 17 such as an optical disk. The reading unit 16 reads the recording medium 17 on which the computer program 121 and various parameters are recorded, and the information is stored in the storage unit 12. The computer program 121 and various parameters may be stored in the storage unit 12 by being downloaded from another computer via a public communication network.

[0044] The map data 18 is digital information of a map that covers a specific area on the earth (for example, all of Japan or the whole world). The map data 18 is made up of multiple layers of data, in which a layer of road data and a layer of background data are superimposed.

[0045] The map data 18 may be stored in a cloud server operated by an information service provider that provides the map data. In this case, the control unit 11 downloads the map data 18 of a predetermined range from the cloud server via the communication unit 13 and a public communication network, and temporarily records the acquired map data 18 of the predetermined range in the memory unit 12 and displays it on the display unit 15.

[0046] The road data in the map data 18 is data that represents actual road alignments as a directed graph formed by nodes 181 and directed links 182. Specifically, the road data is a directed graph in which a plurality of nodes 181 corresponding to intersections, merging points, etc. in an actual road network are connected by directed links 182. Therefore, one-way roads are represented by only one-way links 182. A "link" means a route connecting base points.

[0047] The data assigned to the node 181 includes a node ID. The node ID is an identification number assigned in advance to an intersection, a junction, etc. The data assigned to the node 181 also includes the location information (latitude, longitude, and altitude) of the node.

[0048] An "intersection" is a crossroad, T-junction, or other intersection of two or more roads (or the roadway in the case of roads where the sidewalk and roadway are separated) (Article 2, Paragraph 1, Item 5 of the Road Traffic Act in Japan). A "merging point" is a point where two traffic flows join to form one. Intersections are usually equipped with traffic signal controllers, but merging points often do not have traffic signal controllers.

[0049] The data assigned to the link 182 includes a link ID, which is an identification number of the link 182, and the following information 1) to 4) associated with the link ID: 1) Position information (latitude, longitude, and altitude) of the start point, end point, and interpolation point of the link; 2) Link ID connecting to the start point of the link; 3) Link ID connecting to the end point of the link; and 4) Link cost of the link.

[0050] The link 182 also includes road class information indicating the size of the road (basic roads such as national and prefectural roads in Japan, minor roads, etc.). The map data 18 also includes road type information indicating whether a specific link 182 representing a road is an ordinary road or a toll road, and in-link information indicating whether the link 182 includes a bridge, tunnel, toll gate, etc.

[0051] The background data in the map data 18 includes data on facilities such as rivers, coastlines, administrative boundaries, railway lines, stations, and airports, as well as data on traffic light marks according to the size of intersections.

[0052] At relatively large intersections that use a centralized control system, two or more signal lamp marks are often placed. At relatively small intersections that use an individual control system, only one signal lamp mark or no signal lamp mark is often placed. Therefore, a node 181 with two or more signal lamp marks can be assumed to be an intersection that uses a centralized control system. A node 181 with fewer than two signal lamp marks (one or zero) can be assumed to be an intersection that uses an individual control system.

[0053] The traffic information database 19 includes time-series data in which traffic information such as past link average speeds or link travel times is arranged for each predetermined time period. The database 19 is stored, for example, in a cloud server (hereinafter referred to as a "traffic information server") operated by an information service provider that provides traffic information. The traffic information server generates time-series data of traffic information from probe information including vehicle positions and times, and stores the generated time-series data in the database 19. The database 19 may be included in the storage unit 12. The database 19 may be constructed as a partial area of ​​the storage unit 12.

[0054] [Outline of Information Processing Method] Next, a description will be given of an information processing method executed by the information processing device 1. Specifically, the control unit 11 reads out a computer program 121 from the storage unit 12, and the control unit 11 executes various information processes in accordance with the computer program 121, thereby achieving the following series of information processing methods.

[0055] First, the outline of the information processing method will be explained. First, a user who wishes to check a target intersection that requires constant adjustment specifies extraction conditions for the target intersection to the information processing device 1. Specifically, the user operates the operation unit 14 to input input data X1 including the extraction conditions to the information processing device 1.

[0056] Based on the input data X1, the control unit 11 extracts a plurality of target nodes Nt1 (hereinafter also referred to as "target intersections Nt1") that meet the extraction conditions from a plurality of nodes 181 included in the map data 18. Specifically, the control unit 11 extracts a plurality of target intersections Nt1 by narrowing down the plurality of nodes 181 based on geographical conditions, time conditions, and traffic index conditions.

[0057] Finally, the control unit 11 generates output data Y1 including the extracted target intersection Nt1, and displays the output data Y1 on the display unit 15 so that the user can visually confirm the location of the target intersection Nt1. The user can confirm the target intersection Nt1 by looking at the display unit 15. For example, the user can actually go to the target intersection Nt1 shown on the display unit 15 and adjust the constants of the traffic signal controller (for example, adjust the green time) to alleviate congestion. The information processing method will be described in detail below.

[0058] [Regarding Input Data X1] First, a user inputs input data X1 to the information processing device 1. The input data X1 includes a plurality of extraction conditions for extracting a target intersection Nt1 from a plurality of nodes 181. The plurality of extraction conditions include a first extraction condition C1 which is a geographical condition, a second extraction condition C2 which is a temporal condition, a third extraction condition C3 which is a traffic index condition, and a fourth extraction condition C4 which is a detection event condition.

[0059] The input data X1 may include extraction conditions other than these extraction conditions C1 to C4. At least one of these extraction conditions C1 to C4 does not have to be specified by the user. For example, if the input data X1 does not include the fourth extraction condition C4 (the fourth extraction condition C4 is not specified by the user), the information processing device 1 may extract, as the target intersection Nt1, the node 181 at which an event set in advance by the computer program 121 is occurring.

[0060] 2 is a diagram showing an example of an input screen 20 for specifying a first extraction condition C1. The first extraction condition C1 is a condition for extracting nodes included in a predetermined geographical range. The first extraction condition C1 includes a geographical range specified by the user (hereinafter referred to as a "specified area"). The input screen 20 is a screen that is first displayed on the display unit 15 when the control unit 11 executes the computer program 121.

[0061] The input screen 20 includes an input box 20A in which a designated area is selected from a pull-down menu. For example, if the user wants to check the target intersection Nt1 included in Chiyoda Ward, Tokyo, the user selects "Chiyoda Ward" from the input box 20A. This designates "Chiyoda Ward" as the designated area of ​​the first extraction condition C1.

[0062] 3 is a diagram showing another example of the input screen 20. The input method for the input screen 20 is not particularly limited as long as the input screen 20 is a screen that allows the user to select a designated area. The input screen 20 in FIG. 3 is a GUI screen 20B that allows the user to directly designate a designated area on a map displayed on the screen. For example, the user designates the designated area as a rectangle by clicking a first corner of the designated area with the mouse pointer P1 and then dragging the mouse pointer P1 to the diagonal corner of the first corner.

[0063] In this case, the control unit 11 extracts the node 181 included in the range selected by the mouse pointer P1 from the map data 18, and sets the data relating to the extracted node 181 as a candidate node in the intersection detection process described below.

[0064] The second extraction condition C2 is a condition for extracting time-series data included in a predetermined time range. The second extraction condition C2 includes a time range specified by the user (hereinafter referred to as a "specified period").

[0065] Traffic conditions can have characteristics in various time ranges, such as seasons, weekdays, holidays, or rush hour (e.g., 7:00 AM to 9:00 AM). For example, in tourist areas, traffic congestion is less likely to occur on weekdays, but tends to be concentrated on holidays. For this reason, the user can estimate a rough time range in which constant adjustments will be required at the target intersection, taking into account the characteristics of the specified area (e.g., whether it is a tourist destination or an office district), and specify that range. This allows the processing volume in the information processing device 1 to be limited to that range, thereby shortening processing time.

[0066] The user may specify a designated period using an appropriate input field, for example. The designated period may be one month from "May 1, 2020" to "May 31, 2020" as in the example of FIG. 1, or may specify "weekdays only" or "holidays only" during that one month, or may specify "commuting hours only" during that one month.

[0067] The third extraction condition C3 is a condition that specifies a traffic index to be used to extract the node 181 from among a plurality of traffic indexes in order to evaluate whether an event has occurred at the node 181. The plurality of traffic indexes include, for example, "congestion length," "delay time," and "traffic volume." The plurality of traffic indexes may be acquired based on, for example, probe information collected from vehicles traveling on the roadway, or may be acquired based on detector information collected by roadside sensors such as vehicle detectors installed on the roadway.

[0068] The congestion length is a traffic index indicating the length of congestion on link 182. The delay time is a traffic index indicating the extra travel time required to pass through link 182 compared to free travel. Instead of the delay time, the travel time of link 182 may be used as a traffic index. The traffic volume is a traffic index indicating the number of vehicles passing a predetermined point (e.g., the end point) of link 182 per unit time. Instead of traffic volume, a traffic index disclosed in International Publication No. 2020 / 071040 (e.g., normalized traffic volume expressed as a ratio of traffic volume to saturation traffic flow rate) may be used. Details of these traffic indexes will be described later.

[0069] The fourth extraction condition C4 is a condition for specifying an event to be used to extract node 181 from among a plurality of events. The plurality of events includes, for example, "unbalanced traffic congestion," "one-way congestion," "multiple stops at traffic lights," "head-on congestion," "bottleneck," "reduced flow rate," "right-turn overflow," and "left-turn overflow." Each of these is an event related to traffic congestion, and is an event for which traffic congestion may be alleviated by adjusting the constants of the traffic signal controller at the target intersection. Details of these events will be described later.

[0070] In the information processing device 1 of this embodiment, the user can specify a traffic index that the user wants to evaluate from among multiple traffic indexes as the third extraction condition C3. Also, the user can specify an event that the user wants to detect from among multiple events as the fourth extraction condition C4. This makes it possible to display suggestions that more precisely meet the user's wishes when suggesting target intersections that require constant adjustment to the user.

[0071] 4 is a diagram showing an example of an input screen 30 for specifying the third extraction condition C3 and the fourth extraction condition C4. For example, after the user specifies the first extraction condition C1 and the second extraction condition C2, the information processing device 1 displays the input screen 30 on the display unit 15.

[0072] The input screen 30 includes a first option 31 for specifying a traffic index, a second option 32 for specifying an event, and an OK button 34. The first option 31 includes a plurality of check boxes 311 for specifying one or more traffic indexes from among a plurality of traffic indexes. In the example of Fig. 4, the congestion length and delay time are specified by the user from among the plurality of traffic indexes.

[0073] The second option 32 includes a plurality of check boxes 321 for specifying one or more events from the plurality of events. The information processing device 1 may make only detectable events among the plurality of check boxes 321 selectable (enabled), and may make other events unselectable (disabled).

[0074] For example, "Decrease in flow rate" in the second option 32 can be detected only when "traffic volume" is used among the traffic indices shown in the first option 31. Therefore, if "traffic volume" is not specified in the first option 31, the check box 321 for "Decrease in flow rate" in the second option 32 may be set as an unselectable invalid box 322. The invalid box 322 is shown, for example, in gray on the display unit 15.

[0075] In contrast, events other than "decrease in flow rate" in the second option 32 can be detected by at least one of the traffic indicators, congestion length and delay time. Therefore, for these events, the check boxes 321 are made selectable as usual. This allows the user to know which of the multiple events can be detected by the currently selected traffic indicator.

[0076] If multiple events have a hierarchy, a pop-up window 33 may be displayed when a higher-level event is selected, allowing the user to specify extraction conditions for the lower-level events of that higher-level event. This allows the user to specify extraction conditions in more detail.

[0077] For example, "traffic congestion imbalance" and "one-way congestion" are events that have a superior-subordinate relationship. Traffic congestion imbalance is an event that indicates a state in which there is a bias in congestion (e.g., bias in congestion length) on an inflow route in a specific direction among multiple inflow routes that flow into the same node 181. Therefore, the event of traffic congestion imbalance can occur if there is a bias in congestion on an inflow route in a specific direction, even if congestion occurs on inflow routes other than the specific direction.

[0078] In contrast, one-way congestion is an event that indicates a state in which congestion exists only on the inflow road in a specific direction among the multiple inflow roads. Therefore, one-way congestion indicates a state in which congestion does not exist on inflow roads other than the specific direction in the congestion imbalance, and corresponds to a lower-level event of the congestion imbalance.

[0079] 4, when the user selects the congestion imbalance check box 321 in the second option 32, a pop-up window 33 is displayed, asking whether or not to limit the congestion imbalance to one-way congestion. The pop-up window 33 includes two radio buttons 331 for alternatively specifying "Limit" or "Do not limit." The user selects one of these radio buttons 331 to specify whether or not to limit the extraction conditions to lower-level events.

[0080] When the user clicks the OK button 34 after the first option 31 and the second option 32 have been specified, the information processing device 1 generates input data X1 according to the user's specifications. In the above example, the generated input data X1 includes "Chiyoda Ward" for the first extraction condition C1, the period from "May 1, 2020" to "May 31, 2020" for the second extraction condition C2, "traffic jam length" and "delay time" for the third extraction condition C3, and "traffic jam imbalance (not limited to one-way traffic jam)," "head-on congestion," and "right-turn overflow" for the fourth extraction condition C4. The information processing device 1 stores the input data X1 in the storage unit 12.

[0081] [Regarding time-series data of traffic information] Fig. 5 is an explanatory diagram showing an example of time-series data of traffic information. As shown in Fig. 5, the time-series data of traffic information stored in the database 19 is data in a table format including columns such as "time," "link 1," "link 2," "link 3," "link 4," and "link 5."

[0082] In the "Time" column, time values ​​are listed in a chronological order, with each time value being a predetermined time (for example, five minutes). The length of the predetermined time may vary depending on the time period. While FIG. 5 illustrates one day's worth of time-series data, the data may also be classified into multiple time-series data, for example, by day of the week.

[0083] The "Link 1" column lists the traffic information value for each time value for Link 1 (link average speed in the example of FIG. 5). The "Link 2" column lists the traffic information value for each time value for Link 2. The same applies to Links 3 to 5.

[0084] 5 illustrates five links, Link 1 to Link 5, but the number of links included in the time-series data of traffic information is not limited to 5. In the example of FIG. 5, the traffic information is link average speed (km / h), but the traffic information may be other information such as link travel time (seconds).

[0085] 6 is a flowchart showing an example of an information processing method executed by the information processing device 1 in response to the designation of input data X1. When the user operates the operation unit 14 to designate input data X1 including extraction condition C4 from various extraction conditions C1, and clicks the OK button 34 (FIG. 4), the information processing device 1 executes a series of information processes to generate output data Y1 based on the input data X1.

[0086] [Intersection Detection Process: Step S1] First, the control unit 11 extracts multiple candidate nodes included in the specified area from the multiple nodes 181, and then detects multiple intersection nodes n1 from the multiple candidate nodes (intersection detection process: Step S1). That is, the control unit 11 extracts multiple intersection nodes n1 that meet the node extraction conditions. Specifically, in the intersection detection process, the control unit 11 excludes a node corresponding to a junction (hereinafter referred to as a "junction node n2") from the multiple candidate nodes.

[0087] If a node 181 in the map data 18 is assigned identification information representing an intersection, in the intersection detection process, the control unit 11 may extract, from the specified area, a node 181 having identification information representing the intersection as the intersection node n1.

[0088] Fig. 7 is a flowchart illustrating the details of the intersection detection process (step S1). Fig. 8 is an example of an intersection node n1 detected in the intersection detection process. Fig. 9 is an example of a junction node n2 excluded from candidate nodes in the intersection detection process.

[0089] The control unit 11 first extracts candidate nodes included in the specified area from the plurality of nodes 181. The control unit 11 appropriately executes the following series of steps (steps ST11 to ST15) for each of the plurality of candidate nodes, and detects an intersection node from the plurality of candidate nodes.

[0090] Specifically, the control unit 11 determines whether the candidate node being considered among multiple candidate nodes is a node 181 at which multiple links 182 terminate (a node 181 that shares the termination points of links 182) (step ST11).

[0091] If the determination result in step ST11 is negative, the control unit 11 determines that the candidate node is not an intersection (step ST12), because the node 181 into which only one link 182 flows is a midpoint set in the middle of one road and is not considered to be the node n1 indicating an intersection.

[0092] If the determination result in step ST11 is positive, the control unit 11 determines whether the number of links sharing the termination point with the candidate node under consideration is two or not (step ST13).

[0093] If the determination result in step ST13 is negative (the number of links is not equal to 2), the control unit 11 determines that the candidate node under consideration is the intersection node n1 (step ST15). This is because, as shown in the example of Fig. 8, the node n1 at which three or more links 182 terminate (four in the example of Fig. 8) can be regarded as an intersection.

[0094] If the determination result in step ST13 is affirmative (the number of links is 2), the control unit 11 determines whether the angle α between the two links is equal to or greater than a predetermined threshold value Th1 (e.g., 30 degrees) (step ST14). The threshold value Th1 is, for example, predefined as a parameter in the computer program 121.

[0095] If the determination result in step ST14 is negative (α<Th1), the control unit 11 determines that the candidate node under consideration is not the intersection node n1 (step ST12). This is because, as shown in the example of Fig. 9, node n2, where two incoming roads that intersect at an angle α less than the threshold value Th1 terminate, can be regarded as a merging point rather than an intersection.

[0096] If the determination result of step ST14 is affirmative (α≧Th1), the control unit 11 determines that the candidate node under consideration is the intersection node n1 (step ST15). For example, the control unit 11 assigns a flag indicating that the candidate node determined to be the intersection node n1 is the intersection node n1. After appropriately executing the above series of processes (steps ST11 to ST15) for all candidate nodes, the control unit 11 ends the intersection detection process (step S1).

[0097] [Incoming Road Detection Process: Step S2] Next, the control unit 11 extracts one or more links where congestion may continue, with the intersection node n1 as the head (downstream end) (incoming road detection process: Step S2). The control unit 11 executes the incoming road detection process only when, for example, at least one event (an event where congestion has already occurred) from among "congestion imbalance," "head-on congestion," and "bottleneck" is selected in the second option 32. The control unit 11 may omit this process in other cases (for example, an event related to a sign of congestion, such as "flow rate decline").

[0098] FIG. 10 is a flowchart illustrating the details of the entering road detection process (step S2). In FIG. 10, "I" is a variable representing the most upstream link of the traffic jam starting from intersection node n1. "J" is a threshold representing the expected maximum traffic jam length (e.g., 2000 m). L(I) is a variable representing the distance from the intersection to the start of the most upstream link. The threshold J is, for example, defined in advance in the computer program 121 as a parameter.

[0099] The control unit 11 executes the following series of steps (steps ST21 to ST23) for each intersection node n1 detected in the intersection detection process (step S1). First, the control unit 11 adds an incoming link terminating at the intersection node n1 to a variable I, and sets the added incoming link as the most upstream link (step ST21). Next, the control unit 11 determines whether L(I)>J holds (step ST22).

[0100] If the determination result of step ST22 is positive (L(I)>J), the control unit 11 ends the process. If the determination result of step ST22 is negative (L(I)≦J), the control unit 11 adds to the variable I the link that has the smallest change in direction from the current most upstream link among the links that flow into the start end of the current most upstream link, sets the link as the new most upstream link, and returns to step ST22 (step ST23).

[0101] 11 is an explanatory diagram showing an example of the most upstream link detected by the incoming road detection process (step S2). In FIG. 11, "N" is one of the multiple intersection nodes n1 extracted by the intersection detection. Link 1 is a link whose end coincides with intersection node N, and the length of link 1 is assumed to be equal to or less than threshold J. Link 2 and link 3 are links whose end coincides with the starting point of link 1.

[0102] In this case, link 1 becomes the most upstream link in step ST21 of Fig. 10, but because link 1 is equal to or less than threshold value J, the determination result in step ST22 is negative. Of links 2 and 3, link 3 is the link with the smallest change in direction relative to link 1. In other words, link 3 is the link that flows most linearly into link 1. Therefore, link 3 is added as the new most upstream link in step ST23 of Fig. 10.

[0103] If the sum of the lengths of link 1 and link 3 exceeds threshold J, the judgment result of the second step ST22 becomes positive, and link 1 and link 3 are extracted as one or more links where congestion may continue with intersection node n1 as the downstream end.

[0104] [Traffic Index Calculation Process: Step S3] Next, the control unit 11 calculates one or more traffic indices specified as the third extraction condition C3 (traffic index calculation process: Step S3). Below, as examples of the traffic index calculation process, a congestion length calculation process and a delay time calculation process will be described.

[0105] To calculate the traffic index, the control unit 11 may use various known methods. For example, the control unit 11 may use the technique disclosed in International Publication No. 2022 / 123832 for calculating the congestion length, the technique disclosed in International Publication No. 2022 / 085249 for calculating the delay time, and the technique disclosed in International Publication No. 2020 / 071040 for calculating the normalized traffic volume.

[0106] The control unit 11 calculates the congestion lengths of the links 182 based on time-series data of traffic information for a specified period relating to the links 182 extracted by the entering road detection process (step S2). The control unit 11 stores the calculated congestion lengths in the memory unit 12.

[0107] For example, if the traffic information is a link average speed, the control unit 11 determines that one or more links 182 whose link average speed is equal to or less than a predetermined threshold (e.g., 20 km / h) are congested oncoming roads, and sets the length of the determined congested oncoming roads as the congestion length. The multiple links 182 are a set of links extracted in the oncoming road detection process (step S2) as "one or more links where congestion may continue."

[0108] When the traffic information is link travel time, the control unit 11 determines that one or more links 182 whose link travel time is greater than or equal to a predetermined threshold (e.g., 100 seconds) are congested oncoming roads, and determines the length of the determined congested oncoming roads as the congestion length.

[0109] [Delay Time Calculation Process] The delay time indicates the extra travel time required to pass through a link 182 compared to free travel due to waiting at traffic lights, etc. For the multiple links 182 extracted by the incoming road detection process (step S2), the control unit 11 calculates the travel time when the vehicle travels through the link 182 at an assumed speed Ve (e.g., a specified speed) without waiting at traffic lights as a reference time Trf (Trf = Lm / Ve), where Lm is the link length.

[0110] Next, based on the time-series data of traffic information for the specified period and the reference time Trf, the control unit 11 calculates the delay time dav for each link 182 by subtracting the reference time Trf from the link travel time Tl (dav = Tl - Trf). The control unit 11 stores the calculated delay time dav in the storage unit 12.

[0111] [Event Detection Process: Step S4] Next, the control unit 11 detects one or more target intersections Nt1 where one or more events specified as the fourth extraction condition C4 are estimated to be occurring (event detection process: Step S4). The control unit 11 associates information about the estimated events with the detected target intersections Nt1 and stores the information in the storage unit 12. For example, if only a congestion imbalance is estimated for the target intersection Nt1, the control unit 11 sets the congestion imbalance flag to "1" and stores information about other events set to "0" in the storage unit 12. The detection process will be described in detail below for each event.

[0112] [Traffic congestion imbalance detection process] The control unit 11 detects, from among multiple intersection nodes n1, nodes where the difference in congestion length (or delay time) between the intersecting incoming roads is large, as one or more target intersections Nt1 where a traffic congestion imbalance is estimated to have occurred.

[0113] 12 is an explanatory diagram showing an example of a traffic congestion imbalance detected by the control unit 11. A southbound oncoming road R1, an eastbound oncoming road R2, a northbound oncoming road R3, and a westbound oncoming road R4 all enter an intersection N. In this case, a pair of opposing oncoming roads (e.g., oncoming roads R1 and R3) are likely to belong to the same aspect, and therefore may be treated as a single group.

[0114] The congestion lengths of the four inflow routes R1 to R4 are referred to as L1 to L4, respectively. In the example of Fig. 12, the congestion length L1 of the inflow route R1 is 200 m, the congestion length L2 of the inflow route R2 and the congestion length L3 of the inflow route R3 are 0 m (no congestion on the inflow routes R2 and R3), and the congestion length L4 of the inflow route R4 is 600 m.

[0115] The longer of the congestion length L2 of the incoming road R2 and the congestion length L4 of the incoming road R4 is defined as the congestion length Lx1 in the east-west direction, and the longer of the congestion length L1 of the incoming road R1 and the congestion length L3 of the incoming road R3 is defined as the congestion length Ly1 in the north-south direction. In the example of Figure 12, the congestion length Lx1 is 600 m, and the congestion length Ly1 is 200 m.

[0116] When the absolute value of the difference between the congestion length Lx1 and the congestion length Ly1 (400 in FIG. 12) is equal to or greater than a predetermined threshold value Th2 (|Lx1-Ly1|≧Th2), there is a possibility that an imbalance has occurred between the east-west congestion and the north-south congestion. Therefore, when the above inequality is satisfied, the control unit 11 detects the intersection N as a target intersection Nt1 where an imbalance in congestion is estimated to have occurred.

[0117] At intersection N where congestion imbalance is occurring, if constant adjustment is made, such as extending the green time of the traffic signal controller in the direction where congestion imbalance is greatest (the east-west direction in the example of FIG. 12 ), it is highly likely that the congestion starting from intersection N will be alleviated. For this reason, the information processing device 1 makes it possible to select "congestion imbalance" in the fourth extraction condition C4 as one of the events for which constant adjustment is proposed.

[0118] Furthermore, if the value of the congestion length Lx1 or the congestion length Ly1 at the target intersection Nt1 where a congestion imbalance is estimated is "0," this means that congestion is occurring on only a pair of oncoming roads (or one oncoming road) at the intersection N. The control unit 11 detects the intersection N as the target intersection Nt1 where a "one-way congestion" is estimated to have occurred.

[0119] "One-way congestion" is an event in which the congestion is more uneven than "unbalanced congestion." Therefore, at an intersection N where one-way congestion occurs, the congestion is more likely to be alleviated by the constant adjustment described above. For this reason, the information processing device 1 makes "one-way congestion" selectable in the fourth extraction condition C4 as one of the events for which constant adjustment is proposed.

[0120] When the absolute value of the difference between congestion length Lx1 and congestion length Ly1 is less than a predetermined threshold Th2 (|Lx1 - Ly1| < Th2), there is no significant imbalance between congestion in the east-west direction and congestion in the north-south direction. For example, this inequality is satisfied when there is no congestion in either the east-west direction or the north-south direction, or when congestion is at a similar level in both directions. In the former case, there is no need to alleviate the congestion in the first place. In the latter case, adjusting the green time of the traffic signal controller at intersection N will only result in congestion being concentrated on one of the oncoming roads, and there is little chance of congestion easing. For this reason, the control unit 11 does not detect intersection N as the target intersection Nt1 when the absolute value of the difference between congestion length Lx1 and congestion length Ly1 is less than the predetermined threshold Th2.

[0121] In the above example, the control unit 11 detects congestion imbalance and one-way congestion based on the congestion length, but the control unit 11 may also detect congestion imbalance and one-way congestion based on delay time. For example, in the example of Figure 12, the delay time T1 of the inflow route R1 is 20 seconds, the delay time T2 of the inflow route R2 and the delay time T3 of the inflow route R3 are 0 seconds (no congestion on the inflow routes R2 and R3), and the delay time T4 of the inflow route R4 is 90 seconds.

[0122] As in the case of congestion length, the longer of the delay time T2 on the inflow road R2 and the delay time T4 on the inflow road R4 is defined as the east-west delay time Tx1, and the longer of the delay time T1 on the inflow road R1 and the delay time T3 on the inflow road R3 is defined as the north-south delay time Ty1. In the above example, the delay time Tx1 is 90 seconds, and the delay time Ty1 is 20 seconds.

[0123] When the absolute value of the difference between the delay time Tx1 and the delay time Ty1 (70 seconds in the above example) is greater than or equal to a predetermined threshold value Th3 (|Tx1-Ty1|≧Th3), the control unit 11 detects the intersection N as a target intersection Nt1 where a congestion imbalance is estimated to have occurred.

[0124] [Detection process for multiple stops at traffic lights] The control unit 11 detects, from among multiple intersection nodes n1, nodes where a delay time longer than a multiple of the red time of the traffic signal controller is occurring, as one or more target intersections Nt1 where multiple stops at traffic lights are estimated to have occurred.

[0125] For example, in the example of Figure 12, assume that the red light time in the east-west direction at intersection N is Trx1, and the red light time in the north-south direction at intersection N is Try1. In this case, if the delay time T2 or T4 on either of the east-west oncoming roads R2 or R4 is longer than twice the red light time Trx1 (OR (T2 > 2 × Trx1, T4 > 2 × Trx1)), it is estimated that two or more traffic jams have occurred at a traffic light on either of the east-west oncoming roads R2 or R4.

[0126] If the delay time T1, T3 on either of the north-south oncoming roads R1, R3 is longer than twice the red light time Try1 (OR (T1>2×Try1, T3>2×Try1)), it is estimated that two or more traffic jams while waiting for a traffic light have occurred on either of the north-south oncoming roads R1, R3. Therefore, if any of the above OR inequalities is satisfied, the control unit 11 detects the intersection N as a target intersection Nt1 where multiple traffic jams while waiting for a traffic light are estimated to have occurred.

[0127] At intersection N where multiple stops at traffic lights occur, adjusting the constants, such as extending the green time of the traffic lights, is likely to alleviate the congestion that begins at intersection N. For this reason, the information processing device 1 makes "multiple stops at traffic lights" selectable in the fourth extraction condition C4 as one of the events for which constant adjustments are proposed.

[0128] In the above example, the control unit 11 detects multiple stops at traffic lights based on the delay time, but the control unit 11 may also detect multiple stops at traffic lights based on the congestion length. For example, if the congestion length is longer than twice the length Lwt that a vehicle can travel during one green light period, there is a high possibility that the vehicle will have to wait at traffic lights two or more times to pass through the intersection N. For this reason, the control unit 11 detects the intersection N as a target intersection Nt1 where multiple stops at traffic lights are estimated to have occurred if the congestion length L1 to L4 on any of the incoming roads R1 to R4 is longer than twice Lwt.

[0129] [Processing for detecting congestion ahead] The control unit 11 detects, from among a plurality of intersection nodes n1, nodes to which congestion extends from an intersection node located downstream of the intersection node n1 as one or more target intersections Nt1 where congestion ahead is estimated to have occurred.

[0130] 13 is an explanatory diagram showing an example of a forward jam detected by the control unit 11. In FIG. 13, intersection N is an intersection for which a forward jam is to be detected, and intersection Nx is an intersection located downstream of intersection N (hereinafter referred to as a "downstream intersection Nx"). A forward jam refers to a state in which a traffic jam extends from the downstream intersection Nx to intersection N. When a forward jam occurs, vehicles cannot pass through intersection N in the direction of the downstream intersection Nx, and there is a high possibility that a new traffic jam will occur at intersection N.

[0131] In response to this, if a constant adjustment is made, such as adjusting the offset (the difference in the start time of the green period) of the traffic signal controller at intersection N relative to downstream intersection Nx1, it is highly likely that congestion at intersection N can be avoided. For this reason, the information processing device 1 makes it possible to select "headway congestion" in the fourth extraction condition C4 as one of the events for which a constant adjustment is proposed.

[0132] 13 shows a state where there is no congestion ahead. For example, if the value Lf (= Lm - L2) obtained by subtracting the congestion length L2 of the oncoming road from the link length Lm of the oncoming road leading from intersection N to the downstream intersection Nx is equal to or greater than a predetermined threshold Th4 (Lf ≥ Th4), there is free space for a vehicle to enter on the oncoming road, and the control unit 11 determines that there is no congestion ahead at intersection N. The threshold Th4 is, for example, the length that one vehicle can enter during congestion, and is the sum (e.g., 9 m) of the vehicle length (e.g., 5 m) and the inter-vehicle distance (e.g., 4 m) during congestion.

[0133] The lower part of Fig. 13 shows a state where there is a blockage ahead. For example, if the value Lf is less than a predetermined threshold value Th4 (Lf<Th4), there is no free space for a vehicle to enter on the entering road, and the control unit 11 determines that there is a blockage ahead at the intersection N. Fig. 13 shows an example in which the link length Lm of the entering road is equal to the congestion length L2 of the entering road, and the value Lf is "0," indicating that there is a blockage ahead. In such a case, the control unit 11 detects the intersection N as a target intersection Nt1 where a blockage ahead is estimated to have occurred.

[0134] [Bottleneck detection process] The control unit 11 detects, from among multiple intersection nodes n1, nodes where congestion extends to an intersection node located upstream of the intersection node n1 and where there is no congestion on the link 182 downstream of the intersection node n1, as one or more target intersections Nt1 where a bottleneck is estimated to have occurred.

[0135] Fig. 14 is an explanatory diagram showing an example of a bottleneck detected by the control unit 11. In Fig. 14, intersection N is an intersection targeted for bottleneck detection, intersection Nx1 is an intersection located downstream of intersection N (hereinafter referred to as "downstream intersection Nx1"), and intersection Nx2 is an intersection located upstream of intersection N (hereinafter referred to as "upstream intersection Nx2"). The upstream intersection Nx2, intersection N, and downstream intersection Nx1 are consecutive along the road. Vehicles can legally travel from the upstream intersection Nx2, through intersection N, to the downstream intersection Nx1 without using a turn signal.

[0136] A bottleneck refers to a state in which there is no congestion between intersection N and downstream intersection Nx1, and congestion extends from intersection N to upstream intersection Nx2. In this case, intersection N is the starting point (bottleneck) of the congestion, so if constant adjustment is made, such as extending the green time of the traffic signal controller at intersection N in the direction of downstream intersection Nx1, the congestion starting from intersection N is likely to be alleviated. For this reason, the information processing device 1 makes it possible to select "bottleneck" in the fourth extraction condition C4 as one of the events for which constant adjustment is proposed.

[0137] The control unit 11 detects the intersection N as a target intersection Nt1 where a bottleneck is estimated to have occurred if the congestion length L21 of the incoming road R21 flowing from the intersection N into the downstream intersection Nx1 is equal to or less than a threshold value Th5, and the difference between the link length Lm of the incoming road R22 flowing from the upstream intersection Nx2 into the intersection N and the congestion length L22 of the incoming road R22 is equal to or less than a threshold value Th6 (AND (L21≦Th5, Lm−L22≦Th6)). For example, as shown in the example of FIG. 14 , the threshold values ​​Th5 and Th6 are both set to “0,” and the control unit 11 may detect the intersection N as a target intersection Nt1 where a bottleneck is estimated to have occurred if the congestion length of the incoming road R21 is “0 m” and the link length Lm of the incoming road R22 is equal to the congestion length L22 of the incoming road R22.

[0138] [Process for detecting a decrease in flow rate] The control unit 11 detects, from among multiple intersection nodes n1, nodes where the traffic volume has changed from above a threshold to below the threshold while maintaining a high probe rate, as one or more target intersections Nt1 where a decrease in flow rate is estimated to have occurred.

[0139] The probe rate is, for example, the number of probe vehicles per unit length of the link 182, and is traffic information indicating the number of vehicles traveling on the link 182. The probe rate is included in the time-series data of traffic information in the database 19.

[0140] A decrease in flow rate means that the number of vehicles passing through intersection N per unit time has decreased while the probe rate remains high. Although the number of vehicles traveling on link 182 flowing into intersection N remains relatively high, the number of vehicles passing through intersection N has decreased, which means that there is a high possibility of congestion occurring at intersection N in the future.

[0141] In this case, if constant adjustment is made, such as extending the green time of the traffic signal controller at the intersection N, it is highly likely that congestion at the intersection N can be avoided. For this reason, the information processing device 1 makes it possible to select "decrease in flow rate" in the fourth extraction condition C4 as one of the events for which constant adjustment is proposed.

[0142] The control unit 11 detects the intersection N as a target intersection Nt1 where a decrease in flow rate is estimated to have occurred, for example, if, during a specified period, the probe rate of the link 182 flowing into the intersection N is greater than or equal to the threshold value Th7 and there is a time when the traffic volume at the intersection N changes from greater than or equal to the threshold value Th8 to less than the threshold value Th8 (the traffic volume decreases to less than the threshold value Th8).

[0143] [Right-turn overflow detection process] The control unit 11 detects, from among multiple intersection nodes n1, nodes where congestion occurs in the right-turn vehicle lane when there is no congestion in the straight lane, as one or more target intersections Nt1 where right-turn overflow is estimated to have occurred.

[0144] 15 is an explanatory diagram showing an example of right-turn overflow detected by the control unit 11. In FIG. 15, an entrance road R5 entering an intersection N from the west includes two straight lanes R51 and R52 and a right-turn-only lane R53. The length of the right-turn-only lane R53 is Lrg. If the length Lc of the queue of vehicles waiting to turn right on the entrance road R5 exceeds the length Lrg of the right-turn-only lane R53 (Lc>Lrg), the queue of vehicles waiting to turn right will overflow into the straight lane R52 adjacent to the right-turn-only lane R53, as shown in FIG. 15.

[0145] In this case, even if there is no congestion in the straight lanes R51, R52, one of the straight lanes R51, R52 will be blocked, increasing the possibility of congestion occurring on the merging road R5 in the future. Therefore, if the traffic signal controller at intersection N is an arrow-type traffic signal, adjusting the constants, such as extending the right-turn arrow time of the traffic signal controller, will likely prevent congestion at intersection N. For this reason, the information processing device 1 makes "right-turn overflow" selectable in the fourth extraction condition C4 as one of the events for which constant adjustment is proposed.

[0146] It is assumed that probe information is acquired for each of the multiple lanes R51, R52, and R53, and that the time-series data of traffic information in database 19 is information for each of the multiple lanes R51, R52, and R53. Time-series data of link average speeds (or link travel times) for each of the straight lanes R51 and R52 and the right-turn-only lane R53 is stored in database 19. The control unit 11 calculates a traffic index (e.g., delay time or normalized traffic volume) for each of the multiple lanes R51, R52, and R53 in a traffic index calculation process (step S3).

[0147] Next, in the event detection process (step S4), the control unit 11 detects the intersection N as a target intersection Nt1 where right-turn overflow is estimated to have occurred if the congestion length in the straight lanes R51, R52 is equal to or less than the threshold value Th9 (no congestion in the straight lanes R51, R52) and the congestion length in the right-turn-only lane R53 (the length Lc of the queue of vehicles waiting to turn right) exceeds the length Lrg of the right-turn-only lane R53. The above is an example of the process for detecting right-turn overflow, but left-turn overflow can also be detected in the same way as right-turn overflow.

[0148] [Output Processing: Step S5] Next, the control unit 11 generates output data Y1 for visually displaying one or more target intersections Nt1 on the display unit 15 (output processing: Step S5). Finally, the control unit 11 causes the display unit 15 to display a display screen SC1 including the target intersections Nt1 based on the output data Y1.

[0149] [Display Example 1 of Target Intersection] Figure 16 is an explanatory diagram illustrating a display screen SC1. The display screen SC1 includes a setting window 40 and a map window 50. The setting window 40 is a window for setting events to be displayed and display conditions in the map window 50. The setting window 40 includes check boxes 41 for selecting events to be displayed and radio buttons 42 for alternatively specifying display conditions.

[0150] A check box 41 is provided for each event (an event that the control unit 11 has targeted for detection in the event detection process) specified in the second option 32 of the input screen 30 (FIG. 4). Then, the target intersection Nt1 where the event for which the user has checked the check box 41 has been detected is displayed in the map window 50.

[0151] The radio button 42 is a button that selectively specifies whether, when multiple events are selected in the checkbox 41, the target intersection Nt1 where any of these events is occurring is to be displayed in the map window 50 (or button), or whether only the target intersection Nt1 where these events are occurring overlappingly is to be displayed in the map window 50 (and button).

[0152] 16 , when the user selects "traffic congestion imbalance" and "head-off" from the check boxes 41 using the operation unit 14 and selects the "or" button from the radio buttons 42, the control unit 11 displays the target intersection Nt1 where at least one of traffic congestion imbalance and head-off has been detected in the map window 50. This allows the user to comprehensively grasp multiple events in a single map window 50.

[0153] The user may wish to narrow down the display to only target intersections Nt1 where multiple events are occurring at the same time (target intersections where constant adjustment is considered to be more necessary). In such a case, the user selects multiple events (e.g., "unbalanced traffic congestion" and "head-on congestion") using the check boxes 41 and selects the "and" button among the radio buttons 42. This causes the control unit 11 to display only target intersections Nt1 where multiple events are occurring at the same time in the map window 50. This allows the user to identify target intersections Nt1 where constant adjustment is particularly necessary among the various target intersections Nt1.

[0154] As described above, the control unit 11 can transition between a state (or state) in which the target intersection Nt1 at which any of the plurality of events is detected is output to the display unit 15, and a state (and state) in which only the target intersection Nt1 at which multiple overlapping events are detected is output to the display unit 15. This allows the user to easily grasp the traffic situation by viewing the map window 50 while switching between a comprehensive grasp of the target intersection Nt1 and a limited grasp of the target intersection Nt1, and allows the user to efficiently narrow down the target intersections Nt1 for which constant adjustment should actually be performed.

[0155] The map window 50 includes a map 51 including roads and intersections, and a pie chart 52 displayed near the target intersection Nt1 where an event was detected. Instead of the pie chart 52, an icon may be displayed indicating which intersection in the map 51 is the target intersection Nt1.

[0156] 16, the control unit 11 displays the number of occurrences of an event that occurred during a specified period by changing the size of the pie chart 52. When the event is "unbalanced congestion" or "one-way congestion," the control unit 11 displays the ratio of the congestion length (or delay time) of the intersecting incoming roads by using sectors within the pie chart 52. These occurrence numbers and ratios may be displayed in graphs of other shapes, such as bar graphs, instead of the pie chart 52.

[0157] In the example of Figure 16, "traffic congestion imbalance" and "heading down" are displayed. A pie chart 52 including a sector is displayed at a target intersection Nt1 where only "traffic congestion imbalance" is detected, and a pie chart 52 without a sector is displayed at a target intersection Nt1 where only "heading down" is detected. A double-circle pie chart 52 including a sector is displayed at a target intersection Nt1 where both "traffic congestion imbalance" and "heading down" are detected. In this way, by varying the shape and color of the pie chart 52 (or other icon) for each event, the user can visually understand which event has been detected at the target intersection Nt1.

[0158] In the information processing device 1 of this embodiment, the control unit 11, in response to a predetermined operational input (e.g., double-clicking on the pie chart 52) ​​to the map window 50 shown in Fig. 16, causes the display unit 15 to display, as a display screen SC3, the analysis results of the time-series transition of traffic indices such as congestion length at the target intersection Nt1 specified by the operational input. The display screen SC3 will be described later.

[0159] [Display Example 2 of Target Intersection] The screen that the control unit 11 displays on the display unit 15 based on the output data Y1 is not limited to the display screen SC1 as long as it allows the user to grasp the target intersection Nt1. For example, the display screen SC2 may be displayed instead of the display screen SC1. Furthermore, transitions between the display screens SC1 and SC2 may be possible. For example, the control unit 11 may switch the display on the display unit 15 from the display screen SC1 to the display screen SC2 when the user performs a predetermined operation input (for example, clicking a switching button not shown).

[0160] 17 is an explanatory diagram illustrating the display screen SC2. The display screen SC2 is a screen that displays, in a table format, the name of the extracted target intersection Nt1, the number of occurrences of each event, and, if a congestion imbalance is detected, the average congestion length difference for the extracted target intersection Nt1. In this way, the control unit 11 may display information about the target intersection Nt1 to the user as text and numerical information. This allows the user to quantitatively grasp the traffic conditions at the target intersection Nt1.

[0161] When there are multiple target intersections Nt1 where an event has been detected, the control unit 11 places an intersection at a higher position in the table in accordance with the number of occurrences of a predetermined event (e.g., congestion imbalance). The control unit 11 may rearrange the intersections in order of the number of occurrences of the event in response to a predetermined operation by the user on the column of each event (e.g., double-clicking on the column indicating the number of occurrences of congestion ahead).

[0162] In the example of Figure 17, intersections No. 3 and 4 (Toyotamanaka 2-chome and Toyotama Viabashi) do not have dedicated right-turn lanes, so the control unit 11 displays "-", meaning "no data", as the number of occurrences of right-turn overflow. The control unit 11 displays the numerical value of the average congestion length difference for each intersection name in the column for average congestion length difference.

[0163] In the information processing device 1 of this embodiment, the control unit 11, in response to a predetermined operation input to the table shown in Fig. 17, causes the display unit 15 to display, as a display screen SC3, the analysis results of the time series transition of traffic indices such as congestion length at a target intersection designated by the operation input. The display screen SC3 will be described later.

[0164] [Display example of analysis results] Fig. 18 is an explanatory diagram illustrating a display screen SC3. The display screen SC3 is displayed on the display unit 15 in response to the following operation inputs a1 and a2. Operation input a1: a mouse click or touch operation on the pie chart 52 or the target intersection on the display screen SC1. Operation input a2: a mouse click or touch operation on the intersection name included in the display screen SC2.

[0165] The display screen SC3 includes a setting window 60 and a graph window 70. The setting window 60 is a window for setting traffic indicators to be displayed in the graph window 70. The setting window 60 includes check boxes 61 for selecting traffic indicators to be displayed.

[0166] A check box 61 is provided for each traffic index (traffic index that the control unit 11 has selected as a calculation target in the traffic index calculation process) specified in the first option 31 on the input screen 30 (FIG. 4). The traffic indexes selected by the user in the check boxes 61 are displayed in the graph window 70.

[0167] The graph window 70 displays, in the form of a line graph, the time series transition of traffic indicators at the target intersection Nt1 specified by user input. In the graph window 70, the horizontal axis of the coordinate system represents time, and the vertical axis represents traffic indicators at the entrance roads of the target intersection Nt1. Multiple line graphs represent traffic indicators at each time for entrance roads 1 to 4 of the specified target intersection Nt1.

[0168] In the example of FIG. 18 , the user selects only the check box 61 for "traffic jam length," and the graph window 70 displays the time series transition of the traffic jam length. For example, if the user selects multiple traffic indicators (e.g., "traffic jam length" and "delay time") using the check boxes 61, the multiple traffic indicators are each displayed in the graph window 70. The user can determine in which time period constant adjustment should be performed based on the position and shape of the line graph. In particular, since the graph window 70 can display one or more traffic indicators specified by the user, the user can grasp the traffic situation at the target intersection Nt1 in more detail.

[0169] As described above, according to the information processing device 1 of this embodiment, the control unit 11 extracts intersection nodes corresponding to intersections included in a geographical range (designated area) designated by the user from the nodes included in the map data 18. The control unit 11 acquires time-series data of traffic information for a time range (designated period) designated by the user from the database 19 of time-series data of traffic information.

[0170] The control unit 11 extracts target intersections that require constant adjustment of traffic signal controllers from the extracted intersection nodes based on the acquired time-series data of traffic information, and outputs the extracted target intersections on the display unit (see FIGS. 16 and 17). This allows the user to know in advance which intersections are target intersections based on the target intersections displayed on the display unit 15. This allows the user to easily determine whether or not there are target intersections within the specified area.

[0171] In particular, the control unit 11 extracts target intersections based on one or more traffic indicators selected by the user from among multiple traffic indicators, and can therefore present the user with a more comprehensive list of target intersections that require constant adjustment, according to the user's wishes.

[0172] Modifications of the embodiment will be described below. In the following modifications, the same components as those in the embodiment will be denoted by the same reference numerals and the description thereof will be omitted.

[0173] [First Modification] The node extraction condition (first extraction condition C1) may include a specification of the number of arranged traffic light marks in addition to (or instead of) specifying a geographical range. For example, the user specifies an upper limit for the number of arranged traffic light marks when specifying the input data X1. In this case, in the intersection detection process (step S1), the control unit 11 extracts, as candidate nodes, nodes 181 included in the map data 18 that have the number of arranged traffic light marks equal to or less than the upper limit.

[0174] In this way, the intersection node n1 to be extracted can be narrowed down to nodes where the number of signal lamp marks arranged in the map data 18 is equal to or less than the upper limit. Therefore, it is possible to output to the display unit 15 only target intersections of the scale desired by the user (for example, relatively small intersections that are presumed to use the independent control system).

[0175] [Second Modification] The node extraction conditions (first extraction conditions C1) may include a designated class indicating a road scale designated by the user. In this case, in the intersection detection process (step S1), the control unit 11 extracts, as candidate nodes, nodes 181 included in the map data 18 that are connected to links 182 whose road class is the designated class.

[0176] In this way, the intersection node n1 to be extracted can be narrowed down to nodes connected to links 182 whose road class is the specified class in the map data 18. Therefore, it is possible to output to the display unit 15 only target intersections of the scale desired by the user (for example, relatively small intersections that are presumed to use the independent control system).

[0177] [Third Modification] Instead of a period specified by the user, a predetermined period set in advance in the computer program 121 or the like may be used as the second extraction condition C2. For example, the most recent predetermined period from the time of execution of the computer program 121 (e.g., the most recent one hour, 24 hours, or five days) may be set as the second extraction condition C2. Furthermore, the time range of the time series data may not be limited, and all time series data stored in the database 19 may be the extraction target.

[0178] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present disclosure is not limited to the above-described embodiments, but includes all modifications within the scope of equivalents to the configurations described in the claims.

[0179] Each process (each function) in the above-described embodiments is realized by a processing circuit including one or more processors. The processing circuit may be configured as an integrated circuit or the like that combines one or more memories, various analog circuits, and various digital circuits in addition to the one or more processors. The one or more memories store programs (instructions) that cause the one or more processors to execute each of the processes. The one or more processors may execute each of the processes according to the program read from the one or more memories, or may execute each of the processes according to a logic circuit designed in advance to execute each of the processes. The processor may be any of various processors suitable for computer control, such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), and an ASIC (Application Specific Integrated Circuit). Note that the physically separated processors may cooperate with each other to execute the processes. For example, the processors installed in the physically separated computers may cooperate with each other via a network such as a LAN (Local Area Network), a WAN (Wide Area Network), or the Internet to execute the processes. The program may be installed into the memory from an external server device or the like via the network, or may be distributed in a state stored on a recording medium such as a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versatile Disc Read Only Memory), or a semiconductor memory, and then installed into the memory from the recording medium.

[0180] 1 Information processing device 10 Housing 11 Control unit (information processing unit) 12 Storage unit 121 Computer program 13 Communication unit 14 Operation unit 15 Display unit 16 Reading unit 17 Recording medium 18 Map data 181 Node 182 Link 19 Database 20 Input screen 20A Input box 20B GUI screen 30 Input screen 31 First option 311 Check box 32 Second option 321 Check box 322 Disable box 33 Pop-up window 331 Radio button 34 OK button 40 Setting window 41 Check box 42 Radio button 50 Map window 51 Map 52 Pie chart 60 Setting window 61 Check box 70 Graph window X1 Input data Y1 Output data C1 First extraction condition (node ​​extraction condition) C2 Second extraction condition (temporal condition) C3 Third extraction condition (index condition) C4 Fourth extraction condition (event condition) n1 Intersection node n2 Merging point node Nt1 Target node (target intersection) R1, R2, R3, R4, R5, R21, R22 Entrance road R51, R52 Straight lane R53 Right-turn-only lane L1, L2, L3, L4, L21, L22, Lx, Ly Congestion length T1, T2, T3, T4, Tx, Ty Delay time Th1, Th2, Th3, Th4, Th5, Th6, Th7, Th8, Th9 Threshold Nx1 Downstream intersection Nx2 Upstream intersection SC1, SC2, SC3 Display screen

Claims

1. A processing device comprising: a control unit that executes information processing in accordance with input data entered by a user, wherein the input data includes node extraction conditions for extracting, from among multiple nodes included in map data, multiple intersection nodes that are to be evaluated as to whether or not the intersections are target intersections that require constant adjustment of traffic signal controllers; and index conditions that specify a traffic index to be used for the evaluation from among multiple traffic indexes, and the information processing includes: a first process that extracts one or more intersection nodes that meet the node extraction conditions; a second process that calculates, based on time-series traffic information data, the traffic index specified by the index conditions for the intersection node extracted in the first process or a route connecting to the intersection node; a third process that extracts one or more target intersections from among the multiple intersection nodes extracted in the first process based on the traffic index calculated in the second process; and a fourth process that outputs the one or more target intersections extracted in the third process to a display unit.

2. The processing device according to claim 1, wherein the index conditions include congestion length, delay time, and traffic volume as at least one of the plurality of traffic indexes.

3. The processing device according to claim 1 or claim 2, wherein when a plurality of traffic indicators are specified as the indicator condition, the control unit outputs a plurality of traffic indicators to the display unit for one target intersection extracted in the third process.

4. The processing device according to any one of claims 1 to 3, wherein the input data further includes an event condition that specifies an event to be used in extracting the target intersection from among a plurality of events that require the constant adjustment, and wherein the control unit, in the third process, extracts the target intersection at which the event specified in the event condition was detected from among the intersection nodes extracted in the first process based on the traffic index calculated in the second process.

5. The processing device according to claim 4, wherein the event condition includes at least one of the following as a plurality of events: congestion imbalance, congestion on one side, multiple stops at traffic lights, congestion ahead, bottleneck, flow rate reduction, right turn overflow, and left turn overflow.

6. The processing device according to claim 4 or claim 5, wherein, when a plurality of events are specified as the event condition, the control unit is capable of transitioning in the fourth process between a state in which the target intersection at which a plurality of events are detected overlapping is output to the display unit, and a state in which the target intersection at which any of the plurality of events is detected is output to the display unit.

7. A processing device according to any one of claims 1 to 6, wherein the node extraction conditions include at least one of: a designated area, which is a geographical range designated by the user; an upper limit value for the number of placements designated by the user; and a designated class, which represents the road scale designated by the user; and wherein the control unit, in the first processing, if the node extraction conditions include the designated area, extracts nodes included in the designated area; if the node extraction conditions include the upper limit value, extracts nodes in the map data for which the number of placements of traffic light marks is equal to or less than the upper limit value; and if the node extraction conditions include the designated class, extracts nodes connected to a route in the map data whose road class is the designated class.

8. A processing device according to any one of claims 1 to 7, wherein the input data further includes a time condition that limits a time range within the time series data for which it is evaluated whether the intersection is the target intersection, and wherein the control unit, in the second processing, calculates the traffic index based on data from the time series data that meets the time condition.

9. A processing method executed by a processing device having a control unit that executes information processing in response to input data entered by a user, wherein the input data includes: node extraction conditions for extracting, from among multiple nodes included in map data, multiple intersection nodes that are to be evaluated as to whether or not they are target intersections that require constant adjustment of traffic signal controllers; and index conditions for specifying, from among multiple traffic indexes, a traffic index to be used for the evaluation; the processing method includes: a first step of extracting one or more intersection nodes that meet the node extraction conditions; a second step of calculating, based on time-series traffic information data, the traffic index specified by the index conditions for the intersection node extracted in the first step or for a route connecting to the intersection node; a third step of extracting one or more target intersections from among the multiple intersection nodes extracted in the first step, based on the traffic index calculated in the second step; and a fourth step of outputting the one or more target intersections extracted in the third step to a display unit.

10. A computer program that causes a computer to function as a processing device equipped with a control unit that executes information processing in response to input data entered by a user, wherein the input data includes node extraction conditions for extracting, from among multiple nodes included in map data, multiple intersection nodes that are to be evaluated as to whether or not the intersection is a target intersection requiring constant adjustment of a traffic signal controller, and index conditions for specifying a traffic index to be used for the evaluation from among multiple traffic indexes, and the computer program causes the computer to execute the following steps: a first step of extracting one or more intersection nodes that meet the node extraction conditions; a second step of calculating, based on time-series traffic information data, the traffic index specified by the index conditions for the intersection node extracted in the first step or for a route connecting to the intersection node; a third step of extracting one or more target intersections from among the multiple intersection nodes extracted in the first step based on the traffic index calculated in the second step; and a fourth step of outputting the one or more target intersections extracted in the third step to a display unit.

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