The travel scene illustrated in FIG. 2A corresponds to an actual travel scene of the subject vehicle V. That is, in the travel scene illustrated in FIG. 2A, the subject vehicle V is traveling on a road with two lanes on each side. The traveling direction of vehicles in lanes L1 and L2 is from the lower side to upper side (from the near side to far side) of the drawing, and the traveling direction of vehicles in lanes L3 and L4 is from the upper side to lower side (from the far side to near side) of the drawing. The road on which the subject vehicle V is traveling intersects with a road with one lane on each side ahead of the subject vehicle V. On the road with one lane on each side, the traveling direction of vehicles in a lane L5 is from the right side to left side of the drawing, and the traveling direction of vehicles on a lane L6 is from the left side to right side of the drawing.

As illustrated in FIG. 2A, the area in which the two roads intersect is an intersection C. The intersection C is provided with crosswalks CW1 and CW2 for pedestrians and bicycles to cross the road with two lanes on each side and crosswalks CW3 and CW4 for pedestrians and bicycles to cross the road with one lane on each side. In addition, it is assumed that the intersection C is installed with traffic lights. In the travel scene illustrated in FIG. 2A, it is assumed that vehicles traveling in the lanes L1 and L3 can travel straight ahead or turn left at the intersection C and vehicles traveling in the lanes L2 and L4 can travel straight ahead or turn right at the intersection C. In addition, it is assumed that a destination Px (not illustrated) is set by an occupant of the subject vehicle V at a position that can be reached after traveling straight ahead in the lane L5 to the left side of the drawing.

In this case, the navigation device 16 uses the driving assistance function of the control unit 20 to set a travel route R of the subject vehicle V. For example, the navigation device 16 sets the travel route R illustrated in FIG. 2A. The travel route R is a route for traveling in the lane L1, turning left at the intersection C, traveling in the lane L5, and arriving at the destination Px. As illustrated in FIG. 2A, the subject vehicle V travels in the lane L1 along the travel route R.

The travel of the subject vehicle V is controlled by the autonomous travel control using the driving assistance function of the driving assistance device 19. A plurality of assistance levels are set for the driving assistance executed by the driving assistance device 19. The assistance levels are those indicating an extent to which the driving assistance device 19 intervenes in the control of the driving operations of the subject vehicle V (i.e., an extent to which the driver's manual operation intervenes). The driving assistance device 19 uses its driving assistance function to achieve the driving assistance defined at each assistance level. The assistance levels can be set, for example, based on the driving automation levels defined in SAE J3016: September 2016, Taxonomy and Definitions for Terms Related to Driving Automation Systems for On-Road Motor Vehicles, published by the Society of Automotive Engineers (SAE).

In the travel scene illustrated in FIG. 2A, it is assumed that the driving assistance device 19 is executing the driving assistance, for example, at an assistance level 4 that is a level at which the driving assistance device 19 executes all driving tasks of the subject vehicle V and continuously executes, in a limited area, a response to cases in which continued control is difficult. In this case, when approaching the intersection C, the driving assistance device 19 decelerates the subject vehicle V and detects the state of the traffic lights installed at the intersection C and pedestrians and bicycles crossing the crosswalks CW1 and CW3. Then, when the state of the traffic lights does not instruct the subject vehicle V to make a stop and there are no pedestrians or bicycles crossing the crosswalk CW1 or CW3, the driving assistance device 19 determines that the subject vehicle V can turn left at the intersection C and enters the intersection C.

When this series of determinations and autonomous travel control are executed by the driving assistance device 19, if appropriate information cannot be provided to the occupants of the subject vehicle V, the occupants of the subject vehicle V will feel anxious. That is, if the subject vehicle V enters the intersection C by the autonomous travel control without determining the state of the traffic lights and without providing a determination and its result to avoid contact with pedestrians or bicycles, the occupants of the subject vehicle V may become anxious that the subject vehicle V may suddenly make a stop before or in the intersection C. The driving assistance device 19 of the present embodiment therefore controls the display device 18 so as to be able to provide the occupants of the subject vehicle V with appropriate information. This control is achieved mainly by the functions of the acquisition unit 21, recognition unit 22, determination unit 23, and provision unit 24.

The acquisition unit 21 has a function of acquiring an intersection area (i.e., the intersection area acquisition function) on the travel route R that is set by the autonomous travel control. The intersection area intersects with an area in which other moving objects can move. The other moving objects refer to traffic participants other than the subject vehicle V, such as other vehicles, motorcycles, bicycles, and pedestrians. The area in which other moving objects can move refers to an area in which traffic participants other than the subject vehicle V can move when moving from their current positions to their destinations. For example, the area in which pedestrians can move is an area in which pedestrians can walk, such as a sidewalk, a crosswalk, or a footbridge. The area in which other vehicles and motorcycles can move is an area of a road in which these can travel like the subject vehicle V.

The driving assistance device 19 uses the intersection area acquisition function of the acquisition unit 21 to acquire the travel route R from the navigation device 16. Then, the driving assistance device 19 acquires the intersection area on the travel route R. The intersection area intersects with an area in which other moving objects can move. The travel route R intersecting with an area in which other moving objects can move means that when a traffic participant other than the subject vehicle V is present in an area in which the traffic participant can move, if the subject vehicle V travels along the travel route R, the subject vehicle V and the other moving object will come into contact with each other. That is, in this situation, the travel route R of the subject vehicle V and the area in which the traffic participant other than the subject vehicle V can move are present on the same plane, and when viewed in a plane, the travel route R of the subject vehicle V overlaps with part or all of the area in which the traffic participant other than the subject vehicle V can move.

For example, when a crosswalk is present on the travel route R and a pedestrian is present on the crosswalk, if the subject vehicle V travels along the travel route R, the subject vehicle V will come into contact with the pedestrian. The crosswalk present on the travel route R is therefore an intersection area. In contrast, when a footbridge is present on the travel route R and a pedestrian is walking on the footbridge, even if the subject vehicle V travels along the travel route R, the subject vehicle V and the pedestrian will not come into contact with each other. This is because the road on which the subject vehicle V travels and the footbridge on which the pedestrian walks are not present on the same plane.

The map information 14 includes road information of the roads which the subject vehicle V passes through when traveling along the travel route R. The map information 14 also includes information on the areas in which traffic participants other than the subject vehicle V can move on the roads which the subject vehicle V passes through, and attributes of the areas. The driving assistance device 19 can therefore use the intersection area acquisition function of the acquisition unit 21 to extract the intersection areas present on the travel route R.

Specific examples of intersection areas include an intersection at which a road on which the subject vehicle V travels intersects with a road on which other vehicles travel, and a crosswalk installed on a road on which the subject vehicle V travels. In addition, in a case in which the subject vehicle V enters a facility located at a position facing a road, when a sidewalk is provided between the roadway and the facility, the sidewalk facing the facility is an intersection area. That is, when a pedestrian is walking on the sidewalk between the facility and the roadway, if the subject vehicle V enters the facility, the subject vehicle V and the pedestrian will come into contact with each other, so the sidewalk is an intersection area.

In the case of the travel scene illustrated in FIG. 2A, when another vehicle is present in the intersection C, if the subject vehicle V enters the intersection C, the subject vehicle V may come into contact with the other vehicle. The intersection C is therefore an intersection area. In addition, when the subject vehicle V travels straight through the intersection C, if a pedestrian or a bicycle is crossing the crosswalk CW1 or CW2, the subject vehicle V may come into contact with the pedestrian or the bicycle. The crosswalks CW1 and CW2 are therefore intersection areas. Likewise, when the subject vehicle V turns left at the intersection C, the crosswalks CW1 and CW3 are intersection areas, while when the subject vehicle V turns right at the intersection C, the crosswalks CW1 and CW4 are intersection areas.

The recognition unit 22 has a function of recognizing the travel environment around the subject vehicle V (i.e., the travel environment recognition function). The driving assistance device 19 uses the travel environment recognition function of the recognition unit 22 to recognize the travel environment of the subject vehicle V through acquiring the detection results of the imaging device 11 and ranging device 12 and performing processes such as pattern matching and sensor fusion on the acquired detection results. For example, the driving assistance device 19 detects another vehicle traveling around the subject vehicle V from the detection result of the imaging device 11 and detects, from the detection result of the ranging device 12, the distance from the subject vehicle V to the other vehicle and the direction in which the other vehicle is present relative to the subject vehicle V. The driving assistance device 19 thus recognizes the position of the other vehicle relative to the subject vehicle V. Additionally or alternatively, the driving assistance device 19 detects a pedestrian crossing the crosswalk ahead of the subject vehicle V from the detection result of the imaging device 11 and detects the distance from the subject vehicle V to the pedestrian from the detection result of the ranging device 12. The driving assistance device 19 thus recognizes the position of the pedestrian relative to the subject vehicle V.

The intersection C, which is an intersection area, may be installed with traffic lights. In order to recognize the state of the traffic lights as the travel environment, the driving assistance device 19 uses the travel environment recognition function of the recognition unit 22 to determine whether or not a traffic light is present ahead of the subject vehicle V from the detection result of the imaging device 11 and the map information 14. Then, when a determination is made that a traffic light is present ahead of the subject vehicle V, the driving assistance device 19 detects the state of the traffic light as the travel environment. The state of the traffic light is, for example, the state of lighting of the traffic light, and specific examples include a red light state of the traffic light (i.e., the subject vehicle V must make a stop before the intersection C), a yellow light state of the traffic light (i.e., the subject vehicle V cannot enter the intersection C except a case in which the subject vehicle V cannot make a stop), and a green light state of the traffic light (i.e., the subject vehicle V can enter the intersection C). The state of the traffic light is detected from the image acquired by the imaging device 11.

In the case of the travel scene illustrated in FIG. 2A, the driving assistance device 19 uses the travel environment recognition function of the recognition unit 22 to detect a preceding vehicle and a following vehicle traveling in the lane L1, a vehicle traveling in the lane L2 parallel to the subject vehicle, and oncoming vehicles traveling in the lanes L3 and L4, for example, as other vehicles. Then, the driving assistance device 19 recognizes the positions of the other vehicles traveling around the subject vehicle V from the directions and distances of the other vehicles relative to the subject vehicle V. In the travel scene illustrated in FIG. 2A, no vehicles other than the subject vehicle V are traveling, so it is recognized that there are no other vehicles traveling around the subject vehicle V. In addition, the driving assistance device 19 detects pedestrians crossing the crosswalks CW1, CW2, CW3, and CW4 and recognizes the presence of pedestrians as the travel environment of the subject vehicle V. In the travel scene illustrated in FIG. 2A, no pedestrians are detected, so it is recognized that there are no pedestrians around the subject vehicle V. Furthermore, the driving assistance device 19 determines whether or not a traffic light is installed at the intersection C. In the travel scene illustrated in FIG. 2A, it is assumed that traffic lights are installed at the intersection C and the state of the traffic lights is a yellow light state.

The determination unit 23 has a function of determining, based on the travel environment of the subject vehicle V recognized by the travel environment recognition function, whether or not the subject vehicle V can pass through the intersection area (i.e., the passage determination function). The driving assistance device 19 uses the passage determination function of the determination unit 23 to determine whether or not an obstacle is present in the intersection area, and when determining that no obstacle is present in the intersection area, the driving assistance device 19 determines that the subject vehicle V can pass through the intersection area. On the other hand, when determining that an obstacle is present in the intersection area, the driving assistance device 19 determines that the subject vehicle V cannot pass through the intersection area.

In addition to this, when a traffic light is installed in the intersection area (specifically, at the intersection C), the driving assistance device 19 determines whether or not the state of the traffic light is a state of instructing to make a stop. Then, when determining that the state of the traffic light is a state of instructing to make a stop (i.e., the red light state), the driving assistance device 19 determines that the subject vehicle V cannot pass through the intersection area, while when determining that the state of the traffic light is not a state of instructing to make a stop (i.e., the green light state), the driving assistance device 19 determines that the subject vehicle V can pass through the intersection area.

As for the yellow light state, the driving assistance device 19 determines, based on the traveling state of the subject vehicle V (particularly the traveling speed of the subject vehicle V) and the distance from the subject vehicle V to the intersection area (intersection C), whether or not the subject vehicle V can make a stop before the intersection C. When determining that the subject vehicle V cannot make a stop before the intersection C, the driving assistance device 19 determines that the state of the traffic light is not a state of instructing to make a stop and that the subject vehicle V can pass through the intersection area. On the other hand, when determining that the subject vehicle V can make a stop before the intersection C, the driving assistance device 19 determines that the state of the traffic light is a state of instructing to make a stop and that the subject vehicle V cannot pass through the intersection area.

Thus, such as in the case of an intersection installed with traffic lights, provided that it is necessary to determine the presence or absence of an obstacle in the intersection area and the state of the traffic lights, when determining that no obstacle is present in the intersection area and the state of the traffic lights is not a state of instructing to make a stop, the driving assistance device 19 determines that the subject vehicle V can pass through the intersection area. In contrast, when determining that an obstacle is present in the intersection area or when determining that the state of the traffic lights is a state of instructing to make a stop, the driving assistance device 19 determines that the subject vehicle V cannot pass through the intersection area. Also when the subject vehicle V makes a stop before the intersection area and then makes a start, the driving assistance device 19 determines whether or not the subject vehicle V can pass through the intersection area. For example, when the subject vehicle V makes a stop before the intersection C in accordance with a stop signal and then makes a start, the driving assistance device 19 determines whether or not the subject vehicle V can pass through the intersection C.

In the case of the travel scene illustrated in FIG. 2A, the intersection C is installed with traffic lights, and the driving assistance device 19 therefore determines the presence or absence of an obstacle in the intersection C and the state of the traffic lights. Regarding the presence or absence of an obstacle, in the travel scene illustrated in FIG. 2A, the driving assistance device 19 uses the travel environment recognition function to recognize, as the travel environment, that there are no other vehicles traveling around the subject vehicle V and that there are no pedestrians around the subject vehicle V. The driving assistance device 19 therefore determines that there are no other vehicles or pedestrians at the intersection C. In contrast, regarding the state of the traffic lights, in the travel scene illustrated in FIG. 2A, the driving assistance device 19 uses the travel environment recognition function to recognize that the state of the traffic lights is a yellow light state. In the travel scene illustrated in FIG. 2A, it is assumed that the distance from the subject vehicle V to the intersection C is sufficient for the subject vehicle V to make a stop before the intersection C. In this case, the driving assistance device 19 determines that the state of the traffic lights is a state of instructing to make a stop. In the travel scene illustrated in FIG. 2A, therefore, the driving assistance device 19 determines that the subject vehicle V cannot pass through the intersection area.

The provision unit 24 has a function of providing an onboard terminal and/or an electronic terminal in the subject vehicle V with information that notifies that the subject vehicle V is approaching an intersection area (i.e., an approach notification function). The onboard terminal and electronic terminal of the subject vehicle V are represented, for example, by the display device 18, but are not limited to this, and examples thereof include a display portion of the instrument panel of the subject vehicle V, a terminal for providing information to the occupants of the subject vehicle V when executing the driving assistance at the above-described assistance level 3 or 4, etc. The driving assistance device 19 uses the approach notification function of the provision unit 24 with the onboard terminal and/or electronic terminal of the subject vehicle V to provide the occupants of the subject vehicle V with information that notifies that the subject vehicle V is approaching an intersection area. In addition, while the subject vehicle V is traveling from its current position to the intersection area, the driving assistance device 19 repeatedly performs the process of passage determination using the passage determination function. Then, the driving assistance device 19 changes the information provided to the onboard terminal and/or electronic terminal in the subject vehicle V (i.e., the information provided to the occupants of the subject vehicle V) in accordance with the obtained determination results.

The information notifying that the subject vehicle V is approaching an intersection area includes information about the intersection area which the subject vehicle V is approaching. For example, that information includes information indicating which of an intersection, a crosswalk, and a sidewalk facing a facility that allows the subject vehicle V to enter, the intersection area corresponds to. In addition to this, that information may include information indicating the distance from the current position of the subject vehicle V to the intersection area. The driving assistance device 19 acquires the current position of the subject vehicle V from the position detection device 15, and when the distance from the current position of the subject vehicle V to the intersection area becomes equal to or less than a predetermined distance, the driving assistance device 19 provides information notifying that the subject vehicle V is approaching the intersection area. The predetermined distance is set as an appropriate distance within a range in which an obstacle in the intersection area can be detected using the imaging device 11 and ranging device 12 of the subject vehicle V, etc.

In addition to this, the information provided by the driving assistance device 19 includes information in accordance with a determination result as to whether or not the subject vehicle V can pass through the intersection area and information regarding the determination of whether or not the subject vehicle V can pass through the intersection area. Specific examples of such information include information indicating whether or not an obstacle is present in the intersection area, information indicating the type of obstacle (i.e., traffic participant) present in the intersection area, information indicating the lighting state of traffic lights installed in the intersection area, and information indicating whether or not the subject vehicle V can pass through the intersection area. These information items are displayed on the display device 18 to display them to the occupants of the subject vehicle V, but instead of this, they may be output as a voice message from a speaker provided in the display device 18. That is, the occupants may be notified that the vehicle is approaching an intersection area only by a voice message such as “You will reach an intersection soon.” The same applies to the information in accordance with the determination result as to whether or not the subject vehicle V can pass through the intersection area and the information regarding the determination of whether or not the subject vehicle V can pass through the intersection area. A recorded voice message or synthetic voice message may be used for the voice message.

These information items may be displayed together with the distance from the subject vehicle V to the intersection area. Alternatively or in addition to this, these information items may be displayed at the position of the intersection area on the travel route R displayed on the display device 18. Alternatively or in addition to this, these information items may be displayed by superimposing them on an image of the outside of the vehicle acquired from the imaging device 11. The display device 18 on which these information items are displayed includes not only a display equipped in the subject vehicle V but also a display of a terminal possessed by an occupant of the subject vehicle V. In the case of an unmanned taxi or the like in which the driving assistance device 19 executes all driving tasks of the subject vehicle V and a supervisor monitors the travel of the subject vehicle V at a remote location away from the subject vehicle V, the above-described information may be displayed on a display provided on a terminal for monitoring the travel of the subject vehicle V.

In the case of the travel scene illustrated in FIG. 2A, the subject vehicle V is approaching the intersection C and needs to decelerate or make a stop, so an image (icon) X with “Intersection soon” written on it is displayed on the display device 18. The image X represents information that notifies that the subject vehicle V is approaching an intersection area. The position at which the image X is displayed is the position of the intersection C on the travel route R displayed on the display device 18. This allows the occupants of the subject vehicle V to confirm that the driving assistance device 19 recognizes that the subject vehicle V is approaching the intersection C. Additionally or alternatively, when the image X is displayed, a sound effect may be output from a speaker provided on the display device 18. The timing of outputting the sound effect is, for example, the same as the display of the image X.

In an area A, an image Y indicating the lighting state of a traffic light is displayed together with an image Va indicating the subject vehicle V and an image D indicating the distance from the subject vehicle V to the intersection C. The distance from the left end of the image D to the position indicated by a black triangle C corresponds to the distance from the subject vehicle V to the intersection C. and the distance from the left end to right end of the image D corresponds to the distance from the subject vehicle V to the destination Px. The image Y illustrated in FIG. 2A represents a horizontal traffic light, which corresponds to the green, yellow, and red light states from the left. The image Y illustrated in FIG. 2A indicates the yellow light state corresponding to the lighting state of the traffic light at the intersection C.

The driving assistance device 19 changes the information provided to the occupants of the subject vehicle V in accordance with the determination result obtained by the passage determination function. Specifically, when determining that the subject vehicle V cannot pass through the intersection area, the driving assistance device 19 increases the degree of emphasis of the display portion for the information displayed on the display device 18. For example, the driving assistance device 19 executes at least one of enlarging the size of the display portion for the information, heightening the color of the display portion for the information, increasing the brightness of the display portion for the information, decreasing the transparency of the display portion for the information, and executing a performance that emphasizes the display portion for the information. Examples of a performance that emphasizes the display portion for the information include making the display portion for the information blink. In this case, a sound effect that calls the attention of the occupants may be output from a speaker provided in the display device 18. In the case in which the display portion for the information is already emphasized, when determining that the subject vehicle V cannot pass through the intersection area, the driving assistance device 19 may maintain the display form of the information without changing the degree of emphasis of the display portion for the information displayed on the display device 18.

On the other hand, when determining that the subject vehicle V can pass through the intersection area, the driving assistance device 19 decreases the degree of emphasis of the display portion for the information displayed on the display device 18. For example, the driving assistance device 19 executes at least one of reducing the size of the display portion for the information, diluting the color of the display portion for the information, lowering the brightness of the display portion for the information, increasing the transparency of the display portion for the information, and executing a performance that makes the display portion for the information less noticeable. Examples of a performance that makes the display portion for the information less noticeable include making the display portion for the information fade out. When determining that the subject vehicle V can pass through the intersection area, the driving assistance device 19 may hide the display portion for the information displayed on the display device 18 and stop provision of the information. In particular, when determining, before the subject vehicle V passes through the intersection area, that the subject vehicle V can pass through the intersection area, even before the subject vehicle V passes through the intersection area, the driving assistance device 19 hides the information notifying that the subject vehicle V is approaching the intersection area and stops provision of the information. This can notify the occupants of the subject vehicle V that the driving assistance device 19 allows the vehicle to travel after determining whether or not it is possible to pass through the intersection area.

FIG. 2B illustrates an image displayed on the display device 18 when the state of the traffic light at the intersection C changes to a red light state after the image X is displayed in the travel scene illustrated in FIG. 2A. In the travel scene illustrated in FIG. 2B, as the subject vehicle V travels, the traveling position of the subject vehicle V in the lane L1 moves to a position closer to the intersection C, and the lengths of an image Da indicating the distances to the intersection C and the destination Px become shorter than those of the image D. In addition, the image illustrating the lighting state of the traffic light at the intersection C changes to an image Ya indicating the red light state.

In the travel scene illustrated in FIG. 2B, the state of the traffic light installed at the intersection C has become a red light state, so the subject vehicle V must make a stop before the intersection C. Accordingly, a determination is made that the subject vehicle V cannot pass through the intersection C (intersection area), and the driving assistance device 19 therefore changes the image X, which is information notifying that the subject vehicle V is approaching the intersection area, to an image Xa in accordance with the determination result. The image Xa is information that notifies the occupants of the subject vehicle V that the subject vehicle V will make a stop before the intersection C, and is displayed at the position of the intersection C. By displaying the image Xa, the occupants of the subject vehicle V can be notified that the subject vehicle V will make a stop at the position at which the image is displayed. In addition to this, the driving assistance device 19 can inform the occupants of the subject vehicle V that the subject vehicle V is executing a determination as to whether or not the vehicle can pass through the crosswalk CW1 and the intersection C. This allows the occupants of the subject vehicle V to be given appropriate information when approaching the intersection C.

The image Xa has a larger display portion than the image X, and the degree of emphasis is increased by using a bold font. This can increase the degree of emphasis of the display: In addition, as in the travel scene illustrated in FIG. 2B, when a traffic light is installed in the intersection area, the driving assistance device 19 may separately provide the occupants with information in accordance with a determination result as to whether or not an obstacle is present in the intersection area and information in accordance with the state of the traffic light. For example, in the case of the travel scene illustrated in FIG. 2B, the determination result as to whether or not an obstacle is present in the intersection area is displayed at the position of the intersection C, and the determination result as to whether or not the lighting state of the traffic light is a state of instructing to make a stop is displayed as the image Ya in the lower area A. This can further increase the degree of emphasis of the display.

FIG. 2C illustrates an image to be displayed on the display device 18 when the image Xa is displayed in the travel scene illustrated in FIG. 2B, the subject vehicle V makes a stop at a position before the intersection C, and then the state of the traffic light changes to a green light state. In the travel scene illustrated in FIG. 2C, the subject vehicle V is traveling at a position on the crosswalk CW1, and the lengths of an image Db indicating the distances to the intersection C and the destination Px become shorter than those of the image Da. In addition, the image illustrating the lighting state of the traffic light at the intersection C changes to an image Yb indicating the green light state. Since the state of the traffic light installed at the intersection C is the green light state, the subject vehicle V does not need to make a stop before the intersection C. In the travel scene illustrated in FIG. 2C, therefore, the image Xa, which notifies the occupants that the subject vehicle V will make a stop before the intersection C, is not displayed.

In the travel scene illustrated in FIG. 2C, it is assumed that a pedestrian crossing the crosswalk CW3 is detected. In this case, in order to notify the occupants that a pedestrian is present on the crosswalk CW3, an image Z is displayed at the position of the crosswalk CW3. The image Z is an image that notifies the occupants of the presence of a pedestrian. Then, in order to notify the occupants that the subject vehicle V has stopped because a pedestrian is crossing, an image Xb with “Pedestrian crossing” written on it is displayed next to the image Z. That is, the image Xa is changed to the image Xb based on the determination as to whether or not the vehicle can pass through the intersection area in the travel scene illustrated in FIG. 2C. The image Xb has a smaller display portion than the image Xa, and the degree of emphasis is reduced by using a normal font instead of a bold font. After the pedestrian has completed crossing the crosswalk CW3, the display of the images Xb and Z is stopped (hidden), and the subject vehicle V turns left at the intersection C and enters the lane L5 using the driving assistance function of the control unit 20.

Specific examples of processing in the driving assistance device 19 will now be described for the cases in which the subject vehicle V turns left and right at the intersection C.

First, the case in which the subject vehicle V turns left at the intersection C will be described. When the subject vehicle V turns left along the travel route R at the intersection C provided with traffic lights, the driving assistance device 19 uses the travel environment recognition function of the recognition unit 22 to detect pedestrians and bicycles crossing the intersection C and the state of the traffic lights, thus recognizing the travel environment. The driving assistance device 19 then uses the passage determination function of the determination unit 23 to determine, based on the state of the traffic lights, whether or not the subject vehicle V can pass through the intersection area. When determining, based on the state of the traffic lights (specifically; the lighting state), that the subject vehicle V can pass through the intersection C, the driving assistance device 19 uses the approach notification function of the provision unit 24 to decrease the degree of emphasis of the display portion for the information to be provided to the occupants of the subject vehicle V. On the other hand, when determining, based on the state of the traffic lights, that the subject vehicle V cannot pass through the intersection C, the driving assistance device 19 increases the degree of emphasis of the display portion for the information to be provided to the occupants of the subject vehicle V or maintains the display portion for the information unchanged.

In addition, after determining, based on the state of the traffic lights, that the subject vehicle V can pass through the intersection C and decreasing the degree of emphasis of the display portion for the information, the driving assistance device 19 determines, based on the detection results of pedestrians and bicycles, whether or not the subject vehicle V can pass through the intersection C. Then, when determining, based on the detection results of the pedestrians and bicycles, that the subject vehicle can pass through the intersection C, the driving assistance device 19 stops providing the occupants with information as to whether or not the vehicle can pass through the intersection C. On the other hand, when determining, based on the detection results of the pedestrians and bicycles, that the subject vehicle V cannot pass through the intersection C, the driving assistance device 19 increases the degree of emphasis of the display portion for the information to be provided to the occupants or maintains the display portion for the information unchanged. This allows the information notifying that the subject vehicle V is approaching the intersection area to be changed stepwise in accordance with the determination as to whether or not the subject vehicle V can pass through the intersection area.

The case in which the subject vehicle V turns right at the intersection C will then be described. When the subject vehicle V turns right along the travel route R at the intersection C provided with traffic lights, the driving assistance device 19 uses the travel environment recognition function of the recognition unit 22 to detect pedestrians, bicycles, and oncoming vehicles of the subject vehicle V that cross the intersection C and the state of the traffic lights, thus recognizing the travel environment. In the case of the travel scene illustrated in FIG. 2A, the oncoming vehicles of the subject vehicle V are vehicles traveling in the lane L3 or lane L4. The driving assistance device 19 then uses the passage determination function of the determination unit 23 to determine, based on the state of the traffic lights (specifically, the lighting state), whether or not the subject vehicle V can pass through the intersection C. When determining, based on the state of the traffic lights, that the subject vehicle V can pass through the intersection C, the driving assistance device 19 uses the approach notification function of the provision unit 24 to decrease the degree of emphasis of the display portion for the information to be provided to the occupants of the subject vehicle V. On the other hand, when determining, based on the state of the traffic lights, that the subject vehicle V cannot pass through the intersection C, the driving assistance device 19 increases the degree of emphasis of the display portion for the information to be provided to the occupants of the subject vehicle V or maintains the display portion for the information unchanged.

In addition, after determining, based on the state of the traffic lights, that the subject vehicle V can pass through the intersection C and decreasing the degree of emphasis of the display portion for the information provided to the occupants of the subject vehicle V, the driving assistance device 19 determines, based on the detection results of the pedestrians, bicycles, and oncoming vehicles, whether or not the subject vehicle V can pass through the intersection C. Then, when determining, based on the detection results of the pedestrians, bicycles, and oncoming vehicles, that the subject vehicle V can pass through the intersection C, the driving assistance device 19 stops providing the occupants with information as to whether or not the vehicle can pass through the intersection C. On the other hand, when determining, based on the detection results of the pedestrians, bicycles, and oncoming vehicles, that the subject vehicle V cannot pass through the intersection C, the driving assistance device 19 increases the degree of emphasis of the display portion for the information to be provided to the occupants or the subject vehicle V or maintains the display portion for the information unchanged. This allows the information notifying that the subject vehicle V is approaching the intersection area to be changed stepwise in accordance with the determination as to whether or not the subject vehicle V can pass through the intersection area.

A procedure when the driving assistance device 19 processes information will be described with reference to FIGS. 3A to 3B. FIGS. 3A to 3B depict an example of a flowchart illustrating information processing executed in the driving assistance system 10 of the present embodiment. The processing described below is executed at predetermined time intervals by the CPU 191, which is a processor of the driving assistance device 19.

First, the intersection area acquisition function of the acquisition unit 21 is used in step S1 of FIG. 3A to acquire the travel route R from the navigation device 16, in subsequent step S2 to acquire from the map information 14 the area in which other moving objects can move, and in subsequent step S3 to acquire the intersection area. Then, in step S4, the travel environment recognition function of the recognition unit 22 is used to acquire the current position of the subject vehicle V from the position detection device 15, and in subsequent step S5, a determination is made whether or not the distance from the subject vehicle V to the intersection area is equal to or less than a predetermined distance. When a determination is made that the distance from the subject vehicle V to the intersection area exceeds the predetermined distance, the process proceeds to step S14 of FIG. 3B. Alternatively, step S5 may be repeated until the distance from the subject vehicle V to the intersection area becomes equal to or less than the predetermined distance. On the other hand, when a determination is made that the distance from the subject vehicle V to the intersection area is equal to or less than the predetermined distance, the process proceeds to step S6.

In step S6, the approach notification function of the provision unit 24 is used to display, at the position of the intersection area on the travel route displayed on the display device 18, an image notifying that the vehicle is approaching the intersection area. Step S6 is followed by step S7 of FIG. 3B, in which the passage determination function of the determining unit 23 is used to determine whether or not the intersection area is installed with a traffic light. When a determination is made that the intersection area is not installed with a traffic light, the process proceeds to step S8, in which an obstacle present in the intersection area is detected, and the process proceeds to step S11. On the other hand, when a determination is made that the intersection area is installed with a traffic light, the process proceeds to step S9, in which the state of the traffic light installed in the intersection area and an obstacle present in the intersection area are detected. Step 9 is followed by step S10, in which a determination is made whether or not the state of the traffic light instructs to make a stop. When a determination is made that the state of the traffic light instructs to make a stop, the process proceeds to step S15. On the other hand, when a determination is made that the state of the traffic light does not instruct to make a stop, the process proceeds to step S11. In step S11, a determination is made whether or not an obstacle is present in the intersection area. When a determination is made that no obstacle is present in the intersection area, the process proceeds to step S12, in which a determination is made that the subject vehicle V can pass through the intersection area.

When a determination is made in step S12 that the subject vehicle V can pass through the intersection area, the process proceeds to step S13. In step S13, the approach notification function of the provision unit 24 is used to decrease the degree of emphasis of the image display as to whether or not the vehicle can pass through the intersection area, or stop (hide) the image display: In subsequent step S14, the driving assistance function of the control unit 20 is used to autonomously control the travel of the subject vehicle V via the vehicle control device 17 so that the subject vehicle V travels along the travel route R. After that, the execution of the routine illustrated in FIG. 3 is stopped, and the display control process in the driving assistance device