JP7819073B2 - Traffic assistance system, traffic assistance method, and program - Google Patents

Description

The present invention relates to a traffic assistance system, a traffic assistance method, and a program.

In recent years, there has been an increase in efforts to provide access to sustainable transportation systems that take into consideration vulnerable traffic participants. To achieve this, efforts are being made to further improve traffic safety and convenience through research and development into safety prevention technologies. In this regard, there is known technology that changes the flashing state or light color of luminous road studs embedded in stop lines or crosswalks on oncoming traffic lanes when a sensor detects a vehicle or pedestrian entering an intersection (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2001-172927

However, safety prevention technologies lacked more precise lighting control in response to changing conditions near crosswalks. This meant that appropriate traffic assistance was not provided to vehicles traveling on the road, potentially resulting in insufficient safety.

In order to solve the above-mentioned problems, one of the objectives of this application is to provide a traffic assistance system, traffic assistance method, and program that can further improve safety through more appropriate traffic assistance. This will ultimately further improve traffic safety and contribute to the development of sustainable transportation systems.

The traffic assistance system, traffic assistance method, and program according to the present invention employ the following configuration.
(1): A traffic assistance system according to one aspect of the present invention includes a sensor device that is installed in a monitored area and that detects objects, including moving bodies, moving within the monitored area; a management unit that manages the status of the monitored area based on the detection results of the sensor device; and a presentation control unit that causes an information presentation device installed in the monitored area to present information regarding the behavior of the moving bodies based on the status, wherein the moving bodies include vehicles moving on roads within the monitored area and traffic participants crossing the road by traversing a crosswalk existing on the road, and the information presentation device includes a first light-emitting unit provided on at least one of both sides of the crosswalk in the direction of travel, and the presentation control unit, based on the status of the monitored area, causes the first light-emitting unit to emit light until the crossing is completed when the road includes a congested lane and an uncongested lane and when a traffic participant is crossing the road by traversing the crosswalk from the congested lane side.

(2): In the above aspect (1), when there is a traffic participant crossing the road by passing through the crosswalk from the congested lane side, and when there is a vehicle approaching the crosswalk from the non-congested lane, the presentation control unit causes the first light-emitting unit to emit light until the crossing is completed.

(3): In the above aspect (1), the presentation control unit causes the first light-emitting unit provided on the less congested lane side of the crosswalk to emit light.

(4): In the above aspect (1), the congested lane includes a lane on which the speed of vehicles traveling on the lane is equal to or less than a predetermined speed.

(5): In the aspect (1) above, the presentation control unit switches between lighting and blinking the first light-emitting unit based on the distance between the crosswalk and a vehicle in the congested lane.

(6): In the above aspect (1), the first light-emitting unit is provided on a stop line for stopping the vehicle that is located on at least one of both sides of the crosswalk.

(7): Another aspect of the present invention provides a traffic assistance system that includes a sensor device installed in a monitored area and that detects objects, including moving objects, moving within the monitored area; a management unit that manages the status of the monitored area based on the detection results of the sensor device; and a presentation control unit that causes an information presentation device installed in the monitored area to present information regarding the behavior of the moving objects based on the status. The moving objects include vehicles moving on roads within the monitored area and traffic participants crossing the road by traversing a crosswalk present on the road. The information presentation device includes a second light-emitting unit provided at a position associated with the crosswalk. The presentation control unit, based on the status of the monitored area, causes the second light-emitting unit to emit light until the crossing is complete if there is a traffic participant crossing the road by traversing the crosswalk during a predetermined time period and if there is a vehicle approaching the crosswalk.

(8): In the aspect (7) above, the presentation control unit reduces the amount of light emitted by the second light-emitting unit when it is lit or flashing as the degree of proximity between the vehicle approaching the crosswalk and the crosswalk increases.

(9): Another aspect of the present invention provides a traffic assistance method in which a computer manages the status of a monitored area based on detection results from a sensor device installed in the monitored area that detects objects, including moving objects, moving within the monitored area, and causes an information display device installed in the monitored area to display information regarding the behavior of the moving objects based on the status. The moving objects include vehicles moving on roads within the monitored area and traffic participants crossing the road by traversing a crosswalk present on the road. The information display device includes a first light-emitting unit provided on at least one side of the crosswalk in the direction of travel. If, based on the status of the monitored area, the road includes congested and uncongested lanes and there is a traffic participant crossing the road by traversing the crosswalk from the congested lane, the information display device illuminates the first light-emitting unit until the crossing is complete.

(10): Another aspect of the present invention provides a traffic assistance method in which a computer manages the status of a monitored area based on detection results from a sensor device installed in the monitored area that detects objects, including moving objects, moving within the monitored area, and causes an information display device installed in the monitored area to display information regarding the behavior of the moving objects based on the status. The moving objects include vehicles moving on roads within the monitored area and traffic participants crossing the road by traversing a crosswalk present on the road, the information display device including a second light-emitting unit provided at a position associated with the crosswalk, and, based on the status of the monitored area, if there is a traffic participant crossing the road by traversing the crosswalk during a predetermined time period and if there is a vehicle approaching the crosswalk, the second light-emitting unit is illuminated until the crossing is completed.

(11): Another aspect of the present invention provides a program that causes a computer to manage the status of a monitored area based on the detection results of a sensor device installed in the monitored area that detects objects, including moving objects, moving within the monitored area, and to present information regarding the behavior of the moving objects on an information display device installed in the monitored area based on the status. The moving objects include vehicles moving on roads within the monitored area and traffic participants crossing the road by traversing a crosswalk existing on the road. The information display device includes a first light-emitting unit installed on at least one side of the crosswalk in the direction of traffic. Based on the status of the monitored area, if the road includes congested and uncongested lanes and there is a traffic participant crossing the road by traversing the crosswalk from the congested lane, the program causes the first light-emitting unit to emit light until the crossing is complete.

(12): Another aspect of the present invention provides a program that causes a computer to manage the status of a monitored area based on the detection results of a sensor device installed in the monitored area that detects objects, including moving objects, moving within the monitored area, and to present information regarding the behavior of the moving objects based on the status on an information display device installed in the monitored area, where the moving objects include vehicles moving on roads within the monitored area and traffic participants crossing the road by traversing a crosswalk present on the road, the information display device including a second light-emitting unit provided at a position associated with the crosswalk, and where, based on the status of the monitored area, there is a traffic participant crossing the road by traversing the crosswalk during a predetermined time period and there is a vehicle approaching the crosswalk, the program causes the second light-emitting unit to emit light until the crossing is completed.

Aspects (1) to (12) above can further improve safety through more appropriate traffic assistance.

1 is a diagram illustrating an example of a schematic configuration of a transportation assistance system 1 according to an embodiment. FIG. 1 is a diagram illustrating an example of the configuration of a sensor device 100. FIG. 2 is a diagram illustrating an example of the configuration of an information presentation device 200. FIG. 3 is a diagram illustrating an example of the configuration of a traffic assistance device 300. FIG. 1 is a diagram showing a first example of information presentation in a transportation assistance system 1. FIG. 10 is a diagram showing a second example of information presentation in the transportation assistance system 1. 10 is a flowchart illustrating an example of a first presentation control process. 10 is a flowchart illustrating an example of a second presentation control process.

Embodiments of the traffic assistance system, traffic assistance method, and program of the present invention will be described below with reference to the drawings. Note that the mobile object in the traffic assistance system of the embodiment includes all objects (mobile objects) traveling on roads, such as two-wheeled, three-wheeled, or four-wheeled vehicles, bicycles, and people (pedestrians). Vehicles include any vehicle that can carry a person (driver) and move on the road, including, for example, single-seater vehicles (micromobility). In the following description, the vehicle will be described as a four-wheeled vehicle. Furthermore, the following description will be given assuming that laws stipulate driving on the left side of the road, but if laws stipulate driving on the right side of the road, the terms left and right can be reversed.

[System configuration]
FIG. 1 is a diagram illustrating an example of a schematic configuration of a traffic assistance system 1 according to an embodiment. The traffic assistance system 1 illustrated in FIG. 1 includes, for example, a sensor device 100, an information presentation device 200, and a traffic assistance device 300. These are communicatively connected, for example, via a network NW. The network NW includes, for example, the Internet, a cellular network, a Wi-Fi network, a wide area network (WAN), a local area network (LAN), a provider device, a wireless base station, and the like. At least a portion of the network NW is connected by wire or wirelessly. The traffic assistance system 1 may include one or more of each of the sensor device 100, the information presentation device 200, and the traffic assistance device 300.

The sensor device 100 is installed in a monitored area and detects objects within the area (including, for example, moving objects within the area). The monitored area is, for example, an area that includes roads on which vehicles 400 and other moving objects, such as pedestrians and cyclists, pass. Roads include, for example, crosswalks without traffic lights and roads with stop lines painted on the road surface. When the monitored area is a road, multiple sensor devices 100 may be installed at predetermined intervals along the road. The sensor device 100 may also include optical sensors and radio wave sensors. Optical sensors are, for example, camera devices, and specifically include stereo cameras, monocular cameras, fisheye cameras, infrared cameras, etc. Radio wave sensors include radar devices, LIDAR (Light Detection and Ranging), and TOF (Time of Flight) cameras, etc. Radar devices emit radio waves, such as millimeter waves, around the sensor device 100 and detect radio waves reflected by objects (reflected waves) to detect at least the object's position (distance and direction). LIDAR irradiates the area around the sensor device 100 with light (or electromagnetic waves with wavelengths similar to light) and measures the scattered light. LIDAR detects the distance from the sensor device 100 to an object based on the time between light emission and reception. The irradiated light is, for example, pulsed laser light. If the area to be monitored includes a road, the sensor device 100 is installed, for example, to capture an image of the area including the road from above the road. The sensor ranges (or the angle of view (image capture range) in the case of a camera device) of the multiple installed sensor devices 100 may or may not overlap at least partially.

The information presentation device 200 is installed near a monitored area and presents information (e.g., information about the behavior of a mobile object) to mobile objects (vehicles, pedestrians, bicycles, etc.) passing through the monitored area. Information about the behavior of a mobile object includes, for example, information to prompt the mobile object to slow down, information to cause the mobile object to avoid contact with an object, and information to notify the mobile object that there is another mobile object nearby. The information presentation device 200 also provides information about the surrounding situation by, for example, controlling the light-emitting state of the light-emitting element (e.g., on, flashing, color, light intensity (amount of light)). The information presentation device 200 may also be provided with a display and/or speaker in addition to (or instead of) the light-emitting element to display images and output sound.

The traffic assistance device 300 monitors the conditions of the area to be monitored based on information obtained from the sensor device 100 via the network NW, and causes the information presentation device 200 to output information based on the monitoring results. The traffic assistance device 300 may be realized, for example, as a server device or storage device incorporated into a cloud computing system. In this case, the functions of the traffic assistance device 300 may be realized by multiple server devices and storage devices in the cloud computing system.

Next, we will explain in detail the functional configurations of the sensor device 100, the information presentation device 200, and the traffic assistance device 300.

[Sensor device]
Fig. 2 is a diagram showing an example of the configuration of the sensor device 100. Note that the example of Fig. 2 shows the configuration when the sensor device 100 is a camera device. The sensor device 100 includes, for example, a communication unit 110, an imaging unit 120, and a control unit 130.

The communication unit 110 communicates with the traffic assistance device 300 and other external devices via the network NW. For example, the communication unit 110 transmits image data captured by the imaging unit 120 to the traffic assistance device. The communication unit 110 may also transmit information received from the traffic assistance device 300 to nearby information presentation devices 200 or surrounding vehicles.

The imaging unit 120 is a digital camera that uses a solid-state imaging element such as a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor). The imaging unit 120 repeatedly captures images of an area including the monitored area at a predetermined interval or at a predetermined timing. The angle of view (captured area) of the imaging unit 120 is fixed. The imaging unit 120 may be a stereo camera, a monocular camera, a fisheye camera, an infrared camera, etc.

If the sensor device 100 is a radio wave sensor, a radar device, LIDAR, or TOF camera may be provided instead of (or in addition to) the imaging unit 120. The sensor device 100 may also be provided with a microphone that picks up ambient sounds.

The control unit 130 controls the overall components of the sensor device 100. For example, the control unit 130 transmits sensor data including an image captured by the imaging unit 120 (hereinafter referred to as a camera image), image capture date and time information, and identification information (e.g., a sensor ID) that identifies the sensor device 100, to the traffic assistance device via the network NW. In addition to (or instead of) the camera image, the sensor data may also include information obtained by various sensors such as a radar device, LIDAR, or microphone.

[Information presentation device]
3 is a diagram showing an example of the configuration of the information presentation device 200. The information presentation device 200 includes, for example, a communication unit 210, a light-emitting unit 220, and a control unit 230.

The communication unit 210 communicates with the traffic assistance device 300 and other external devices via the network NW. For example, the communication unit 210 receives various information transmitted from the traffic assistance device 300.

The light-emitting unit 220 is provided at a position corresponding to road markings such as stop lines and crosswalks on roads in the monitored area. For example, the light-emitting unit 220 may be provided on at least a portion of the stop line or crosswalk, on at least one side of the crosswalk in the direction of traffic (the direction of crossing the road), or near (within a predetermined distance from) the stop line or crosswalk. The light-emitting unit 220, for example, lights up or flashes using one or more light-emitting elements. The light-emitting elements are, for example, LEDs (Light Emitting Diodes), but are not limited to this and may be any light-emitting element that can light up or flash based on a control signal. The light-emitting unit 220 may also emit light in a predetermined color, or in a color instructed by the control unit 230.

The control unit 230 controls all of the components of the information presentation device 200. For example, the control unit 230 controls the lighting, blinking, color, intensity (light amount), etc. of the light-emitting unit 220 based on instructions (control information) from the traffic assistance device 300. Note that if a display or speaker is provided in addition to (or instead of) the light-emitting unit 220, output control for each may be performed based on instructions from the traffic assistance device 300.

[Traffic support device]
4 is a diagram showing an example of the configuration of a traffic assistance device 300. The traffic assistance device 300 includes, for example, a communication unit 310, an acquisition unit 320, an analysis unit 330, a management unit 340, a presentation control unit 350, and a storage unit 360. The acquisition unit 320, the analysis unit 330, the management unit 340, and the presentation control unit 350 are realized by a hardware processor, such as a central processing unit (CPU), executing a program (software). Some or all of these components may be realized by hardware (including circuitry), such as a large-scale integration (LSI), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a graphics processing unit (GPU), or may be realized by a combination of software and hardware. The program may be stored in advance in a storage device, or may be stored in a removable storage medium (non-transient storage medium) such as a DVD or CD-ROM, and installed in the storage device by inserting the storage medium into a drive device.

The storage unit 360 may be realized by the various storage devices described above, or by an SSD, EEPROM, ROM, RAM, etc. The storage unit 360 stores, for example, infrastructure facility information 362, programs, and various other information.

Infrastructure facility information 362, for example, the sensor ID of the sensor device 100 or the identification information (information presentation device ID) of the information presentation device 200 is associated with the installation location, installation orientation (angle of view (photography range), display surface direction), and type information. For example, in the case of the sensor device 100, the type information includes identification information that identifies a stereo camera, monocular camera, fisheye camera, infrared camera, TOF camera, radar device, LIDAR, microphone, etc. Furthermore, in the case of the information presentation device 200, the type information includes identification information that identifies, for example, a light-emitting unit, display, or speaker.

Under the control of the server-side communication control unit 520, the communication unit 310 communicates with the sensor device 100, the information presentation device 200, and other external devices (including moving objects such as vehicles) via the network NW.

The acquisition unit 320 acquires information from the sensor device 100 or other external devices. For example, the acquisition unit 320 acquires sensor data from the sensor device 100. The acquisition unit 320 may also acquire information about the weather, season, etc. of the monitored area from external devices. The acquired data may be stored in the memory unit 360.

The analysis unit 330 analyzes the sensor data acquired by the acquisition unit 320. For example, if the sensor data includes image data, the analysis unit 330 analyzes the image data. For example, the analysis unit 330 converts the image data into a bird's-eye view coordinate system, and then performs image recognition processing using well-known techniques (such as binarization, contour extraction, image enhancement, feature extraction, and pattern matching) based on the converted coordinate system to recognize the surrounding conditions of the sensor device 100. The analysis unit 330 may also perform the above-mentioned image analysis processing without performing coordinate conversion.

For example, the analysis unit 330 identifies an object included in the image data based on the matching results (degree of match) between feature information obtained by analyzing the image data and feature information predetermined for each object. The degree of match may be derived, for example, based on how many of the multiple feature elements included in the feature information match, or based on the similarity of each feature element or the feature information as a whole. The degree of match may also be derived, for example, based on the sum of the differences for each element. The degree of match may also be derived from the two pieces of information being compared using AI (artificial intelligence) functions such as machine learning (neural networks) and deep learning, or may be derived using other methods.

The analysis unit 330 may also recognize the position, type, speed, etc. of objects within the monitored area. Objects include, for example, moving bodies such as the vehicle 400, pedestrians, and bicycles. Objects may also include road structures, etc. Road structures include, for example, road signs, traffic lights, curbs, medians, guardrails, fences, walls, railroad crossings, crosswalks drawn on the road surface, and stop lines (pause lines). Objects may also include obstacles that impede the travel of the host vehicle M.

The analysis unit 330 also recognizes the position (relative position), speed, acceleration, and other status of mobile objects present within the monitored area. The position of an object is recognized, for example, as a position in an absolute coordinate system with the origin at a representative point of the mobile object (such as the center of gravity or the center of the drive shaft). The "status" of an object may include, for example, the acceleration or jerk of the mobile object, or its "behavioral state" (for example, whether it is crossing a pedestrian crossing or about to do so). The analysis unit 330 may also analyze characteristic information such as shape to identify mobile objects included in the monitored area. The analysis unit 330 may also measure the travel time of the mobile object in a specified section.

The analysis unit 330 also identifies moving objects included in the sensor data acquired from the multiple sensor devices 100 based on the degree of match between feature information such as the shape of the moving object. Feature information may include, in addition to shape, patterns (including symbols, numbers, etc. visible from the outside), color, etc. For example, the analysis unit 330 identifies moving objects whose degree of match is equal to or greater than a threshold as the same object, assigns common identification information to those moving objects, and assigns unique identification information to moving objects whose degree of match is less than the threshold. This allows the management unit 340 to manage the movement status of each moving object based on the assigned identification information.

The management unit 340 manages the status of the monitored area (e.g., the movement status of mobile objects) based on the analysis results of the analysis unit 330. For example, the management unit 340 determines whether there are any traffic participants (pedestrians or cyclists) crossing (or attempting to cross) a road at a crosswalk within the area, or whether there are any vehicles approaching the crosswalk. The management unit 340 also manages the congestion status (presence or absence of traffic jams, etc.), weather, etc. in the monitored area.

The presentation control unit 350 provides information to mobile objects moving through the monitored area via the information presentation device 200 installed in that area, based on the situation in that area. The information provided includes, for example, information notifying vehicles that there is a traffic participant crossing the crosswalk, and information notifying traffic participants crossing the crosswalk that a vehicle is approaching, by controlling the light-emitting state (e.g., lighting, blinking, or light intensity) of the light-emitting element of the information presentation device 200. The information provided may also include image and audio information.

[Example of information presentation]
Next, an example of information presentation in the transportation assistance system 1 will be described in detail.

First Example
5 is a diagram illustrating a first example of information presentation in the traffic assistance system 1. The example in FIG. 5 shows sensor devices 100-1 and 100-2 capable of capturing images using a camera or the like of an area including a road RD1 with one lane in each direction (lanes L1 and L2) allowing two-way traffic, a crosswalk CW1 drawn on the road surface of road RD1, and stop lines SL1 and SL2 placed a predetermined distance before the crosswalk CW1 in the direction of travel of each of lanes L1 and L2 of road RD1. In the example in FIG. 5, no traffic signals are installed near the crosswalk CW1.

In the example of FIG. 5, light-emitting units 220-1 and 220-2 of the information presentation device 200 are provided on at least a portion of each of the stop lines SL1 and SL2. Light-emitting units 220-1 and 220-2 are an example of a "first light-emitting unit" provided on at least one of the two sides of the crosswalk CW in the direction of travel (both in the example of FIG. 5). Note that light-emitting unit 220 may be embedded within the rendering area of stop lines SL1 and SL2 so that its light emission is visible, or may be provided near (within a predetermined distance from) stop lines SL1 and SL2. In the example of FIG. 5, vehicle 400-1 is traveling along lane L1 toward crosswalk CW1, and vehicles 400-2 to 400-4 are in lane L2.

Sensor device 100-1 captures an image of an area (monitored area) that includes at least the crosswalk CW1, the stop line SL1, and a lane L1 that is a predetermined distance away from the crosswalk CW1. Sensor device 100-2 captures an image of an area that includes at least the crosswalk CW1, the stop line SL2, and a lane L2 that is a predetermined distance away from the crosswalk CW1. The installation locations and sensor ranges of each sensor device 100-1, 100-2 are stored in advance in the infrastructure information 362 of the traffic assistance device 300 and are managed by the management unit 340.

In the example of FIG. 5, sensor devices 100-1 and 100-2 capture images of a fixed imaging range at a predetermined interval or at a predetermined timing, and transmit sensor data including the captured image data to traffic assistance device 300. Traffic assistance device 300 has analysis unit 330 analyze the sensor data acquired by acquisition unit 320. Based on the analysis results of the sensor data captured by sensor devices 100-1 and 100-2, management unit 340 recognizes that pedestrian P1 is crossing road RD1 by passing through crosswalk CW1, from the relationship between the position, direction of movement, and speed of pedestrian P1 and the position of crosswalk CW1. In this case, management unit 340 causes presentation control unit 350 to execute light emission control of light emitters 220-1 and 220-2 according to the surrounding conditions of crosswalk CW1.

For example, the management unit 340 monitors the congestion status of lane L2 based on the speed and relative positions of each of vehicles 400-1 to 400-4 obtained as an analysis result from the analysis unit 330. For example, if the speed of vehicles 400-1 to 400-4 (the average speed of vehicles traveling in the same lane) is below a predetermined speed (e.g., approximately 20 kph or less), the management unit 340 determines that the lane is congested. "Congested" may include, for example, not only traffic congestion on the road, but also conditions that make it difficult to pass due to on-street parking, or conditions that make it easy for blind spots to form near crosswalks.

In addition to determining based on speed, the management unit 340 may also determine that a lane is congested when the average inter-vehicle distance (which may exclude crosswalk sections) between vehicles 400-2 to 400-4 is less than a predetermined distance. The management unit 340 may also derive the degree of congestion based on the aforementioned vehicle speed and average inter-vehicle distance, and determine that a lane is congested when the degree of congestion is equal to or greater than a threshold. In this case, the smaller the speed and inter-vehicle distance, the greater the degree of congestion. In the example of Figure 5, the management unit 340 determines that lane L1 is not congested and lane L2 is congested.

For example, when lane L2 is congested and pedestrian P1 is crossing road RD1 from lane L2 through crosswalk CW1, the presentation control unit 350 controls the information presentation device 200 to keep the light-emitting unit 220 emitting light until pedestrian P1 finishes crossing. In this case, the presentation control unit 350 turns on or blinks the light-emitting unit 220-1, which is located at a position corresponding to the uncongested lane L1 (on the lane L1 side), among the light-emitting units 220-1 and 220-2. Furthermore, the presentation control unit 350 may turn on or blink the light-emitting unit 220-1 when pedestrian P1 is crossing the road through crosswalk CW1 from the congested lane L2 and when a vehicle 400-1 is approaching crosswalk CW1 from the uncongested lane L1 (located within a predetermined distance from crosswalk CW1). This allows nearby moving objects to be alerted at a more appropriate time, making it easier to avoid collisions between moving objects.

The presentation control unit 350 may adjust the light-emitting state of the light-emitting unit 220-1 based on the status of vehicle 400-3 (the vehicle in the traffic jam) that is located in a position that is likely to create a blind spot at crosswalk CW1 when viewed from vehicle 400-1. For example, the presentation control unit 350 switches between lighting and blinking of the light-emitting unit 220-1 based on the distance between the crosswalk and vehicle 400-3. In this case, the presentation control unit 350 controls the light-emitting unit 220-1 to blink when vehicle 400-3 is present near crosswalk CW1 (within a specified distance), and controls the light-emitting unit 220-1 to light up when vehicle 400-3 is not present near crosswalk CW1. The specified distance may be a fixed distance, or a variable distance that is adjusted based on the road shape, degree of congestion, the shape of vehicle 400-3 (large vehicle, standard car), weather, time of day, etc.

The presentation control unit 350 may also adjust the blinking cycle, the color of the emitted light, or the amount of light depending on the distance between the vehicle 400-3 near the crosswalk CW1 and the crosswalk CW1. In this case, the presentation control unit 350 may speed up the blinking cycle, use a more emphasized color, or increase the amount of light (brighter) so that the closer the distance, the more emphasized the display. The presentation control unit 350 may also adjust the blinking cycle, color, and amount of light depending on the weather, time of day (daytime, nighttime), etc., to make the crosswalk more visible to the occupants of the vehicle 400-1.

In this way, when a traffic participant (pedestrian P1) is crossing road RD1 via crosswalk CW1, vehicle M can illuminate the stop line SL1 in the less congested lane (lane L1 in the figure) to notify vehicle 400-1 approaching crosswalk CW1 of the presence of a traffic participant (pedestrian P1) crossing crosswalk CW1. Therefore, even if vehicle 400-1 cannot see pedestrian P1 because of vehicle 400-3 between the crossing pedestrian P1's position and vehicle 400-1's position, the illumination of stop line SL1 allows the occupant of vehicle 400-1 to recognize pedestrian P1 at an early stage and perform driving operations such as slowing down or stopping vehicle 400-1. Furthermore, the flashing stop line SL1 allows pedestrian P1 to be aware of the presence of vehicle 400-1 (a vehicle approaching the crosswalk) that he or she cannot see, thereby urging him or her to be more vigilant and making it easier for him or her to take action to avoid contact.

In the first embodiment, the presentation control unit 350 may, in addition to blinking the light-emitting unit 220-1 provided at the stop line SL1, also cause the light-emitting unit 220-2 provided at the stop line SL2 on the congested lane L2 side to emit light when the surroundings are dark, depending on the time of day, weather, etc. In this case, the presentation control unit 350 may, for example, control the light-emitting unit 220-2 to emit light in a less conspicuous state than the light-emitting state of the light-emitting unit 220-1 (for example, by reducing the light intensity or slowing down the blinking cycle).

Second Example
FIG. 6 is a diagram illustrating a second example of information presentation in the traffic assistance system 1. The example in FIG. 6 illustrates a scene on road RD1 similar to that in FIG. 5 , in which vehicle 400-5 is traveling in lane L1 at speed V1 toward crosswalk CW1, and vehicle 400-6 is traveling in lane L2 at speed V2 toward crosswalk CW1. In the example in FIG. 6 , in addition to light-emitting units 220-1 and 220-2, light-emitting units 220-3 and 220-4 of the information presentation device 200 are provided in at least a portion of crosswalk CW1 (e.g., in the lateral direction of the road (a line drawn along the Y-axis direction in the figure)). Light-emitting units 220-3 and 220-4 are an example of a "second light-emitting unit" provided at a position associated with crosswalk CW1. Note that light-emitting units 220-1 and 220-2 do not necessarily have to be provided in the second example.

In the second example, when a traffic participant (pedestrian P1) is crossing road RD1 via crosswalk CW1 during a predetermined time period and a vehicle 400 is approaching crosswalk CW1, the presentation control unit 350 controls the light emission state of light-emitting units 220-3 and 220-4 according to the distance between vehicle 400 and crosswalk CW1. The predetermined time period is, for example, a time period when it is dark around crosswalk CW1 (e.g., nighttime), and may be a fixed time period or a variable time period set according to the season or weather.

For example, the presentation control unit 350 reduces the amount of light emitted by the light-emitting units 220-3 and 220-4 when they are lit or flashing as the degree of proximity between the vehicle 400 approaching the crosswalk CW1 and the crosswalk CW1 increases. For example, the degree of proximity increases as the distance D1 between the vehicle 400-5 and the crosswalk CW1 decreases. For example, the presentation control unit 350 initiates light emission control to turn on or flash the light-emitting units 220-3 and 220-4 at a predetermined light intensity when the distance D1 becomes less than a predetermined distance (in other words, when the degree of proximity becomes equal to or exceeds a threshold). Thereafter, the presentation control unit 350 performs light emission control to gradually reduce the light intensity (dims the light) as the vehicle 400-5 approaches the crosswalk CW1 (as the distance D1 decreases). Then, when the pedestrian P1 (traffic participant) has finished crossing the crosswalk or when the vehicle 400-5 has stopped, the presentation control unit 350 stops the light emission of the light-emitting units 220-3 and 220-4.

The presentation control unit 350 may control the light emission state so that the blinking cycle becomes slower as the distance D1 becomes smaller (the degree of approach becomes greater), or so that the blinking cycle becomes faster as the speed V1 of the vehicle 400-5 becomes faster. This makes it possible to more appropriately alert the vehicle 400-5 and pedestrian P1 depending on the situation of surrounding vehicles. In particular, since crosswalks without traffic signals are difficult to see at night, the light emitted by the light-emitting unit 220 can notify the occupants of the vehicle 400-5 of the presence of the crosswalk CW1 and pedestrian P1. Pedestrian P1 can also more accurately grasp that the vehicle 400-5 is approaching, even in conditions at night when it is difficult to see the surrounding situation.

As shown in FIG. 6, when there are multiple vehicles 400-5 and 400-6 approaching crosswalk CW1 from different lanes, the presentation control unit 350 may control the light-emitting state of light-emitting units 220-3 and 220-4 based on the longer of the distance D1 between vehicle 400-5 and crosswalk CW1 and the distance D2 between vehicle 400-6 and crosswalk CW1 (distance D1 in the example of FIG. 6). The presentation control unit 350 may also derive the time it takes for vehicle 400-5 to reach crosswalk CW1 based on distance D1 and the speed V1 of vehicle 400-5, and the time it takes for vehicle 400-6 to reach crosswalk CW1 based on distance D2 and the speed V2 of vehicle 400-6, compare these times, and control the light-emitting state of light-emitting units 220-3 and 220-4 based on the vehicle corresponding to the longer time.

The presentation control unit 350 may also control the light emission of the light-emitting unit 220-3, which is located closer to vehicle 400-5, based on distance D1, and may control the light emission of the light-emitting unit 220-4, which is located closer to vehicle 400-6, based on distance D2. This allows pedestrian P1 to more accurately determine from which direction and to what extent a vehicle is approaching based on the light-emitting state of each of the light-emitting units 220-3 and 220-4. The presentation control unit 350 may also cause the light-emitting unit 220-1 provided at the stop line SL1 and the light-emitting unit 220-2 provided at the stop line SL2 to emit light according to the light-emitting state of the light-emitting units 220-3 and 220-4. The presentation control unit 350 may also adjust the color emitted by the light-emitting unit 220 depending on the time of day, weather, surrounding conditions, etc. This allows the light-emitting state of the light-emitting unit 220 to be more appropriately controlled according to the surrounding conditions.

In the above-described embodiment, an example was described in which sensor data from multiple sensor devices 100-1 and 100-2 was used. However, similar processing may also be performed using sensor data from a single sensor device 100 with a wider sensor range. In the examples of FIGS. 5 and 6, lanes L1 and L2 were oncoming lanes, but similar processing to that described above may also be performed on roads with two or more lanes in which traffic can travel in the same direction. The first and second embodiments may also be performed simultaneously. Furthermore, the presentation control unit 350 may output a sound (such as a warning sound) from the speaker of the information presentation device 200 or display an image on the display of the information presentation device 200 depending on the light-emitting state of the light-emitting units 220-1 to 220-4.

[Processing flow]
Next, a description will be given of the flow of processing executed by the traffic assistance system 1 according to the embodiment. Note that the following description will mainly focus on the presentation control (light emission control) processing by the light emitting unit among the processing executed by the traffic assistance system 1. Furthermore, each processing described below may be repeatedly executed at a predetermined cycle or at a predetermined timing.

Figure 7 is a flowchart showing an example of the first presentation control process. In the example of Figure 7, the presentation control unit 350 determines whether there is a pedestrian crossing from the congested lane (an example of a traffic participant crossing a road) (step S100). If it is determined that there is a pedestrian crossing, the presentation control unit 350 determines whether there is a vehicle approaching the crosswalk where the pedestrian is crossing (step S102). This vehicle is, for example, a vehicle traveling in the opposite lane of the congested lane (an oncoming vehicle).

If it is determined that a vehicle is approaching the crosswalk, the presentation control unit 350 determines whether a vehicle in the congested lane is near the crosswalk (step S104). If it is determined that a vehicle in the congested lane is near the crosswalk, the presentation control unit 350 controls the light-emitting unit 220 provided at the stop line of the lane of travel of the vehicle approaching the crosswalk (the stop line before the crosswalk) to begin flashing (step S106). If it is determined that a vehicle in the congested lane is not near the crosswalk, the presentation control unit 350 controls the light-emitting unit 220 provided at the stop line of the lane of travel of the vehicle approaching the crosswalk to begin lighting up (step S108).

After processing step S106 or step S108, the presentation control unit 350 determines whether the pedestrian has finished crossing the road (step S110). If it is determined that the pedestrian has not finished crossing the road, the process returns to step S104. If it is determined that the pedestrian has finished crossing the road, the presentation control unit 350 stops lighting or blinking the light-emitting unit 220 (step S112), and the process of this flowchart ends.

Furthermore, if it is determined in step S100 that there are no pedestrians crossing from the congested lane, or if it is determined in step S102 that there are no vehicles approaching the crosswalk, the processing of this flowchart ends.

FIG. 8 is a flowchart illustrating an example of the second presentation control process. In the example of FIG. 8, the presentation control unit 350 determines whether a pedestrian is crossing the road at night (a nighttime pedestrian) via a crosswalk (step S120). If it determines that a pedestrian is crossing the road at night, the presentation control unit 350 determines whether a vehicle is approaching the crosswalk (step S122). If it determines that a vehicle is approaching the crosswalk, the presentation control unit 350 controls the light-emitting unit 220 installed at the crosswalk to emit light in stages according to the distance between the vehicle and the crosswalk (step S124). Next, the management unit 340 determines whether the pedestrian has finished crossing the road or whether the approaching vehicle has stopped (step S126). If it determines that the pedestrian has not finished crossing the road and the approaching vehicle has not stopped, the process returns to step S124. Furthermore, if it is determined that the vehicle has finished crossing the road or that the approaching vehicle has stopped, the presentation control unit 350 causes the light emitting unit 220 to stop emitting light (step S128). This ends the processing of this flowchart.

Furthermore, if it is determined in step S120 that there are no pedestrians crossing the road at night, or if it is determined in step S122 that there are no vehicles approaching the crosswalk, the processing of this flowchart ends. Note that the first lighting control and second lighting control described above may be executed simultaneously.

<Modification>
At least a portion of the configuration of the traffic assistance device 300 described above may be provided in the sensor device 100 or the information presentation device 200. Furthermore, at least a portion of the configuration of the sensor device 100 or the information presentation device 200 may be included in the traffic assistance device 300. For example, when the sensor device 100 and the information presentation device 200 are included in the traffic assistance device 300, the presentation control unit 350 has the functions of the control units 130 and 230.

In the embodiment described above, the traffic assistance system 1 includes a sensor device 100 installed in a monitored area that detects objects, including mobile objects, moving within the monitored area; a management unit 340 that manages the status of the monitored area based on the detection results of the sensor device 100; and a presentation control unit 350 that causes an information presentation device 200 installed in the monitored area to present information related to the behavior of the mobile objects. The mobile objects include vehicles moving on roads within the monitored area and traffic participants crossing the road at a crosswalk. The information presentation device 200 includes a first light-emitting unit installed on at least one side of the crosswalk in the direction of traffic (for example, a stop line in front of the crosswalk for stopping vehicles). Based on the status of the monitored area, if the road includes congested and uncongested lanes and there is a traffic participant crossing the road at the crosswalk from the congested lane, the presentation control unit 350 causes the first light-emitting unit to emit light until the crossing is complete, thereby providing more appropriate traffic assistance and further improving safety.

Furthermore, according to an embodiment, the information presentation device 200 includes the above-described sensor device 100, management unit 340, and presentation control unit 350. The information presentation device 200 includes a second light-emitting unit provided at the crosswalk, and the presentation control unit 350, based on the situation in the monitored area, causes the second light-emitting unit to emit light until the crossing is completed when there is a traffic participant crossing the road via the crosswalk during a specified time period and when there is a vehicle approaching the crosswalk, thereby further improving safety through more appropriate traffic assistance. This can therefore further improve traffic safety and contribute to the development of a sustainable transportation system.

For example, according to the embodiment, multiple sensor devices 100 installed in a monitored area can be linked together to more accurately track moving objects and grasp the situation. Furthermore, according to the embodiment, infrastructure equipment such as cameras installed in a specified area can be effectively utilized to provide an infrastructure-cooperative traffic support system.

The above-described embodiment can be expressed as follows.
a storage medium for storing computer-readable instructions;
a processor connected to the storage medium;
The processor executes the computer-readable instructions to:
managing the situation of the monitored area based on the detection results of a sensor device that is installed in the monitored area and detects objects, including moving objects, moving in the monitored area;
displaying information about the behavior of the moving object on an information display device installed in the area to be monitored based on the situation;
The moving objects include vehicles moving on roads within the monitoring area and traffic participants crossing the roads by passing through crosswalks present on the roads;
the information presentation device includes a first light-emitting unit provided on at least one of both sides of the crosswalk in a traffic direction,
If the road includes a congested lane and an uncongested lane based on the situation in the monitored area, and if there is a traffic participant crossing the road from the congested lane side by passing through a crosswalk that exists on the road, the first light-emitting unit is caused to emit light until the crossing is completed.
Traffic assistance system.

The above-described embodiment can be expressed as follows.
a storage medium for storing computer-readable instructions;
a processor connected to the storage medium;
The processor executes the computer-readable instructions to:
managing the situation of the monitored area based on the detection results of a sensor device that is installed in the monitored area and detects objects, including moving objects, moving in the monitored area;
displaying information about the behavior of the moving object on an information display device installed in the area to be monitored based on the situation;
The moving objects include vehicles moving on roads within the monitoring area and traffic participants crossing the roads by passing through crosswalks present on the roads;
the information presentation device includes a second light-emitting unit provided at a position associated with the crosswalk,
based on the situation in the monitored area, if there is a traffic participant crossing the road by passing through a crosswalk that exists on the road during a predetermined time period and if there is a vehicle approaching the crosswalk, the second light-emitting unit is caused to emit light until the crossing is completed.
Traffic assistance system.

The above describes the form for carrying out the present invention using an embodiment, but the present invention is in no way limited to such an embodiment, and various modifications and substitutions can be made without departing from the spirit of the present invention.

1 Traffic assistance system 100 Sensor device 110, 210, 310 Communication unit 120 Imaging unit 130, 230 Control unit 200 Information presentation device 220 Light emitting unit 300 Traffic assistance device 320 Acquisition unit 330 Analysis unit 340 Management unit 350 Presentation control unit 360 Storage unit

Claims (14)

a sensor device that is installed in a monitoring area and detects objects, including moving objects, moving in the monitoring area;
a management unit that manages the situation of the monitoring target area based on the detection results of the sensor device;
a presentation control unit that causes an information presentation device installed in the monitoring area to present information about the behavior of the moving object based on the situation,
The moving objects include vehicles moving on roads within the monitoring area and traffic participants crossing the roads by passing through crosswalks present on the roads;
the information presentation device includes a first light-emitting unit provided on at least one of both sides of the crosswalk in a traffic direction,
the presentation control unit, based on the situation of the monitored area, when the road includes a congested lane and an uncongested lane and when there is a traffic participant crossing the road from the congested lane side by passing through the crosswalk, causes the first light-emitting unit to emit light until the crossing is completed ;
the presentation control unit causes the first light-emitting unit provided on the less congested lane side of both sides of the crosswalk in a traffic direction to emit light.
Traffic assistance system. a sensor device that is installed in a monitoring area and detects objects, including moving objects, moving in the monitoring area;
a management unit that manages the situation of the monitoring target area based on the detection results of the sensor device;
a presentation control unit that causes an information presentation device installed in the monitoring area to present information about the behavior of the moving object based on the situation,
The moving objects include vehicles moving on roads within the monitoring area and traffic participants crossing the roads by passing through crosswalks present on the roads;
the information presentation device includes a first light-emitting unit provided on at least one of both sides of the crosswalk in a traffic direction,
the presentation control unit, based on the situation of the monitored area, when the road includes a congested lane and an uncongested lane and when there is a traffic participant crossing the road from the congested lane side by passing through the crosswalk, causes the first light-emitting unit to emit light until the crossing is completed ;
the presentation control unit switches between lighting and blinking of the first light-emitting unit based on a distance between the crosswalk and a vehicle in the congested lane.
Traffic assistance system. a sensor device that is installed in a monitoring area and detects objects, including moving objects, moving in the monitoring area;
a management unit that manages the situation of the monitoring target area based on the detection results of the sensor device;
a presentation control unit that causes an information presentation device installed in the monitoring area to present information about the behavior of the moving object based on the situation,
The moving objects include vehicles moving on roads within the monitoring area and traffic participants crossing the roads by passing through crosswalks present on the roads;
the information presentation device includes a first light-emitting unit provided on at least one of both sides of the crosswalk in a traffic direction,
the presentation control unit, based on the situation of the monitored area, when the road includes a congested lane and an uncongested lane and when there is a traffic participant crossing the road from the congested lane side by passing through the crosswalk, causes the first light-emitting unit to emit light until the crossing is completed ;
The first light-emitting unit is provided on a stop line for stopping the vehicle that is located on at least one of both sides of the crosswalk.
Traffic assistance system. the presentation control unit causes the first light-emitting unit to emit light until the crossing is completed when there is a traffic participant crossing the road by passing through the crosswalk from the congested lane side and when there is a vehicle approaching the crosswalk from the non-congested lane.
A traffic assistance system according to any one of claims 1 to 3 . The congested lane includes a lane on which the speed of vehicles traveling on the lane is equal to or lower than a predetermined speed.
A traffic assistance system according to any one of claims 1 to 3 . a sensor device that is installed in a monitoring area and detects objects, including moving objects, moving in the monitoring area;
a management unit that manages the situation of the monitoring target area based on the detection results of the sensor device;
a presentation control unit that causes an information presentation device installed in the monitoring area to present information about the behavior of the moving object based on the situation,
The moving objects include vehicles moving on roads within the monitoring area and traffic participants crossing the roads by passing through crosswalks present on the roads;
the information presentation device includes a second light-emitting unit provided at a position associated with the crosswalk,
the presentation control unit, based on the situation of the monitored area, causes the second light-emitting unit to emit light until the crossing is completed when there is a traffic participant crossing the road by passing through the crosswalk during a predetermined time period and when there is a vehicle approaching the crosswalk;
the presentation control unit reduces the amount of light when lit or flashing by the second light-emitting unit as the degree of proximity between the vehicle approaching the crosswalk and the crosswalk increases,
Traffic assistance system. The computer
managing the situation of the monitored area based on the detection results of a sensor device that is installed in the monitored area and detects objects, including moving objects, moving in the monitored area;
displaying information about the behavior of the moving object on an information display device installed in the area to be monitored based on the situation;
The moving objects include vehicles moving on roads within the monitoring area and traffic participants crossing the roads by passing through crosswalks present on the roads;
the information presentation device includes a first light-emitting unit provided on at least one of both sides of the crosswalk in a traffic direction,
If the road includes a congested lane and an uncongested lane based on the situation in the monitored area, and if there is a traffic participant crossing the road from the congested lane side by passing through the crosswalk, the first light-emitting unit emits light until the crossing is completed ;
causing the first light-emitting unit provided on the less congested lane side of both sides of the crosswalk in the traffic direction to emit light;
Transportation support methods. The computer
managing the situation of the monitored area based on the detection results of a sensor device that is installed in the monitored area and detects objects, including moving objects, moving in the monitored area;
displaying information about the behavior of the moving object on an information display device installed in the area to be monitored based on the situation;
The moving objects include vehicles moving on roads within the monitoring area and traffic participants crossing the roads by passing through crosswalks present on the roads;
the information presentation device includes a first light-emitting unit provided on at least one of both sides of the crosswalk in a traffic direction,
If the road includes a congested lane and an uncongested lane based on the situation in the monitored area, and if there is a traffic participant crossing the road from the congested lane side by passing through the crosswalk, the first light-emitting unit emits light until the crossing is completed ;
switching between lighting and blinking of the first light-emitting unit based on the distance between the crosswalk and a vehicle in the congested lane;
Transportation support methods. The computer
managing the situation of the monitored area based on the detection results of a sensor device that is installed in the monitored area and detects objects, including moving objects, moving in the monitored area;
displaying information about the behavior of the moving object on an information display device installed in the area to be monitored based on the situation;
The moving objects include vehicles moving on roads within the monitoring area and traffic participants crossing the roads by passing through crosswalks present on the roads;
the information presentation device includes a first light-emitting unit provided on at least one of both sides of the crosswalk in a traffic direction,
If the road includes a congested lane and an uncongested lane based on the situation in the monitored area, and if there is a traffic participant crossing the road from the congested lane side by passing through the crosswalk, the first light-emitting unit emits light until the crossing is completed ;
The first light-emitting unit is provided on a stop line for stopping the vehicle that is located on at least one of both sides of the crosswalk.
Transportation support methods. The computer
managing the situation of the monitored area based on the detection results of a sensor device that is installed in the monitored area and detects objects, including moving objects, moving in the monitored area;
displaying information about the behavior of the moving object on an information display device installed in the area to be monitored based on the situation;
The moving objects include vehicles moving on roads within the monitoring area and traffic participants crossing the roads by passing through crosswalks present on the roads;
the information presentation device includes a second light-emitting unit provided at a position associated with the crosswalk,
based on the situation in the monitored area, if there is a traffic participant crossing the road by passing through the crosswalk during a predetermined time period and if there is a vehicle approaching the crosswalk, causing the second light-emitting unit to emit light until the crossing is completed;
the amount of light emitted by the second light-emitting unit when lit or flashing decreases as the degree of proximity between the vehicle approaching the crosswalk and the crosswalk increases,
Transportation support methods. On the computer,
managing the situation of the area to be monitored based on the detection results of a sensor device that is installed in the area to be monitored and detects objects, including moving objects, moving in the area to be monitored;
displaying information about the behavior of the moving object on an information display device installed in the area to be monitored based on the situation;
The moving objects include vehicles moving on roads within the monitoring area and traffic participants crossing the roads by passing through crosswalks present on the roads;
the information presentation device includes a first light-emitting unit provided on at least one of both sides of the crosswalk in a traffic direction,
If the road includes a congested lane and an uncongested lane based on the situation in the monitored area, and if there is a traffic participant crossing the road from the congested lane side by passing through the crosswalk, the first light-emitting unit emits light until the crossing is completed ;
causing the first light-emitting unit provided on the less congested lane side of both sides of the crosswalk in the traffic direction to emit light;
program. On the computer,
managing the situation of the area to be monitored based on the detection results of a sensor device that is installed in the area to be monitored and detects objects, including moving objects, moving in the area to be monitored;
displaying information about the behavior of the moving object on an information display device installed in the area to be monitored based on the situation;
The moving objects include vehicles moving on roads within the monitoring area and traffic participants crossing the roads by passing through crosswalks present on the roads;
the information presentation device includes a first light-emitting unit provided on at least one of both sides of the crosswalk in a traffic direction,
If the road includes a congested lane and an uncongested lane based on the situation in the monitored area, and if there is a traffic participant crossing the road from the congested lane side by passing through the crosswalk, the first light-emitting unit emits light until the crossing is completed ;
switching between lighting and blinking of the first light-emitting unit based on the distance between the crosswalk and a vehicle in the congested lane;
program. On the computer,
managing the situation of the area to be monitored based on the detection results of a sensor device that is installed in the area to be monitored and detects objects, including moving objects, moving in the area to be monitored;
displaying information about the behavior of the moving object on an information display device installed in the area to be monitored based on the situation;
The moving objects include vehicles moving on roads within the monitoring area and traffic participants crossing the roads by passing through crosswalks present on the roads;
the information presentation device includes a first light-emitting unit provided on at least one of both sides of the crosswalk in a traffic direction,
If the road includes a congested lane and an uncongested lane based on the situation in the monitored area, and if there is a traffic participant crossing the road from the congested lane side by passing through the crosswalk, the first light-emitting unit emits light until the crossing is completed ;
The first light-emitting unit is provided on a stop line for stopping the vehicle that is located on at least one of both sides of the crosswalk.
program. On the computer,
managing the situation of the area to be monitored based on the detection results of a sensor device that is installed in the area to be monitored and detects objects, including moving objects, moving in the area to be monitored;
displaying information about the behavior of the moving object on an information display device installed in the area to be monitored based on the situation;
The moving objects include vehicles moving on roads within the monitoring area and traffic participants crossing the roads by passing through crosswalks present on the roads;
the information presentation device includes a second light-emitting unit provided at a position associated with the crosswalk,
based on the situation in the monitored area, if there is a traffic participant crossing the road by passing through the crosswalk during a predetermined time period and if there is a vehicle approaching the crosswalk, causing the second light-emitting unit to emit light until the crossing is completed;
the amount of light emitted by the second light-emitting unit when lit or flashing decreases as the degree of proximity between the vehicle approaching the crosswalk and the crosswalk increases,
program.