JP3620093B2 - Car navigation system - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an in-vehicle navigation system, and more particularly to an in-vehicle navigation system that can obtain travel data of other vehicles using inter-vehicle communication.
[0002]
[Prior art]
In-vehicle navigation systems that currently display the current location of the vehicle and the state of the travel locus on a road map set in advance are currently used. In this in-vehicle navigation system, the travel distance of the vehicle is detected by the distance detection sensor, the traveling direction of the vehicle is detected by the direction sensor, the current location of the vehicle is obtained from the detected values by calculation, and the position is determined on the road map. Plot on top and display on the display screen as the vehicle travels. Further, in order to obtain the current position, the GPS (Cross Positioning System) receiver receives the current position information of the vehicle from the artificial satellite with the values of latitude and longitude.
[0003]
A so-called route guidance function is known as one of the functions of the navigation device. This route guidance function displays the route from the current position of the vehicle to the destination on the display screen and guides the vehicle to the destination. That is, when a destination is input by the driver, a route from the current location to the destination is obtained by calculation. At this time, as the guidance route to the destination, a route having the shortest distance is selected from a plurality of routes.
[0004]
[Problems to be solved by the invention]
However, in the conventional navigation device, as described above, the route that is the shortest in distance is selected as the guidance route. However, depending on the road condition such as traffic jam, the shortest route in the distance is It could not be said that this is a route that can be reached.
[0005]
On the other hand, Japanese Patent Application Laid-Open No. 4-295999 proposes a technique for receiving a travel record of another vehicle using inter-vehicle communication and using it as travel data for an in-vehicle navigation system. However, in this technique, since the information that can be input is limited, it is difficult to obtain travel data for selecting a route that can reach the destination in the shortest time.
[0006]
The present invention has been made in order to solve the above-described problems. The object of the present invention is to receive traveling data of other vehicles when vehicles traveling on a road communicate with each other, and the vehicle Another object of the present invention is to provide an in-vehicle navigation system that can be used for route guidance.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, in the in-vehicle navigation system according to claim 1 of the present invention, a destination setting device for setting a destination, a positioning device for positioning the vehicle position,Originated from another vehicleOther carofpositioninformation, A map information storage unit for holding map information, a map information reading device for reading map information from the map information storage unit, the map information read by the map information reading device, and the map information reading unit An in-vehicle navigation system comprising: a route setting device that sets a route to a destination set by a destination setting device based on a current position measured by a positioning device;
Other vehicle received by the other vehicle position receiving deviceofpositioninformationBased on the aboveSettingDrive on a defined routeothercarGuess the number ofTheGuessedThe number of other carsMore than a predetermined numberOther vehicle number judgment means to judge whether or notTheHave
By the other vehicle number judging meansMore than a predetermined numberIf it is determined, the gist is to change the route set by the route setting device.
[0008]
In order to achieve the above object, in the vehicle-mounted navigation system according to claim 2 of the present invention,The other vehicle position receiving device according to claim 1, further comprising:Other carDestination informationReceiveAnd
The other vehicle number judging meansOther vehicle receivedofpositioninformationas well asEyeTarget placeinformationBased on the other vehicle traveling on the set routeThe number of other vehicles estimated is equal to or greater than a predetermined number.Whether or notThatThe gist.
[0009]
In order to achieve the above object, in the in-vehicle navigation system according to claim 3 of the present invention,The other vehicle position receiving device according to claim 1, further comprising:Receive routes to other car destinationsAnd
The other vehicle number judging meansOther vehicle position receivedinformationAnd based on the route to the destination of other vehicles,SaidOther vehicles traveling on the set routeThe number of other vehicles estimated is equal to or greater than a predetermined number.Whether or notThatThe gist.
[0010]
In order to achieve the above object, in the in-vehicle navigation system according to claim 4 of the present invention, a destination setting device for setting a destination, a positioning device for positioning the vehicle position,otherOther vehicle position receiving device for receiving lighting of vehicle position and other vehicle hazard, map information storage unit for holding map information, map information reading device for reading map information from the map information storage unit, and reading the map information A route setting device for setting a route to a destination set by a destination setting device based on map information read by the device and a current position measured by the positioning device. ,
Based on the position of the other vehicle lighting the hazard received by the other vehicle position receiving device, it is determined whether there is another vehicle lighting the hazard on the route set by the route setting device. Other vehicle judgment means,
The gist of the present invention is to have an alerting means for urging the driver to pay attention to another vehicle whose hazard is lit as determined by the other vehicle determination means.
[0012]
[Action]
In the in-vehicle navigation system according to claim 1, the route setting device has a route to the destination set by the destination setting device based on the map information read by the map information reading device and the current position measured by the positioning device. Set. Also,otherVia car position receiverOriginated from another vehicleOther carofpositioninformationReceive. AndOther vehicle number judgment means,Other vehicle received by this other vehicle position receiverofpositioninformationBased onSettingOther vehicles that exist on the specified routeGuess the number ofExtractGuessedWhether the number of other cars is so large that it hinders smooth traffic(Whether more than the predetermined number)JudgingotherThe number of carsThan a predetermined numberIf it is determined that there are many, the route set by the route setting device is changed. For this reason, a route can be set while avoiding a route in which many traveling vehicles are congested.
[0013]
In the in-vehicle navigation system according to claim 2,otherVia car position receiverMoreOther car destinationinformationReceive. And the other vehicle received by this other vehicle position receiving deviceofpositioninformationAnd destinationinformationBased onSettingDrive on a defined routeothercarGuess the number ofIt is determined whether the number of other vehicles is large enough to hinder smooth traffic. AndotherThe number of carsMore than a predetermined numberIf it is determined that there are many, the route set by the route setting device is changed. For this reason, it is possible to set a route while avoiding a route in which there are many traveling vehicles scheduled to go to the same destination and congestion is expected.
[0014]
In the in-vehicle navigation system according to claim 3,otherThe other vehicle position and the route to the destination of the other vehicle are received via the vehicle position receiving device. AndOther vehicle number judgment means,Based on the other vehicle position received and the route to the destination,SettingOther cars scheduled to travel on the specified routeGuess the number ofIt is determined whether the number of other vehicles is large enough to hinder smooth traffic. And the number of other vehicles is determined by this other vehicle number judging means.More than a predetermined numberIf it is determined that there are many, the route set by the route setting device is changed. For this reason, it is possible to set a route while avoiding a route in which there are many traveling vehicles scheduled to go to the same destination and congestion is expected.
[0015]
In the in-vehicle navigation system according to claim 4, the route setting device has a route to the destination set by the destination setting device based on the map information read by the map information reading device and the current position measured by the positioning device. Set. Also,otherThe other vehicle position and the lighting of the hazard of the other vehicle are received by the vehicle position receiving device. Here, based on the position of the other vehicle in which the other vehicle determination means has received the hazard received by the other vehicle position receiving device, there is another vehicle having the hazard lit on the route set by the route setting device. Whether or not to do so is determined, and the alerting means urges the driver to pay attention to the other vehicle determined by the other vehicle determining means. That is, the vehicle whose hazard is lit is informed before the driver's visual observation and is used for safe driving.
[0017]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of an in-vehicle navigation device according to an embodiment of the present invention. In this embodiment, the display unit 20 is arranged in the vehicle interior of the vehicle and the control unit 10 controls the display unit 20. A display screen 21A, a speaker 21B, and a switch 22a are attached to the display unit 20. On the other hand, the control unit 10 includes a map management unit 11, a screen management unit 12, a map data reading unit 13, a map drawing unit 14, an overall management unit 15, and an input management unit 16.
[0018]
The map management unit 11 manages the current position of the vehicle based on the current position input from the current position measurement unit 30. This current position measurement unit 30 detects a beacon receiver 32 that receives a beacon from a beacon transmitter installed on a road, a GPS receiver 34 that receives radio waves from an artificial satellite, and a traveling direction of the vehicle. An azimuth sensor 36 and a distance sensor 38 that detects the travel distance of the vehicle are connected to each other, and are configured to obtain an accurate position by mutually correcting the values detected by these sensors.
[0019]
The screen management unit 12 displays the display image drawn by the map drawing unit 14 on the display screen 21 </ b> A of the display unit 20 based on the control signal from the general management unit 15, and based on the control signal from the general management unit 15. Then, an audio signal is emitted from the speaker 21B of the display unit 20.
[0020]
The map data reading unit 13 inputs the own vehicle speed sent from the speed sensor 27 and signals sent from the turn signal sensor, such as blinker blinking, blinking hazard, etc., and map data from the map information storage unit 40. Read. The map information storage unit 40 includes a digital map data storage unit 42 that stores domestic map information converted into a digital data format, a road data storage unit 44 that stores road data, and a destination map. The destination data storage unit 46 stores data, and the map coordinate data storage unit 48 stores map coordinate data.
[0021]
The overall management unit 15 manages the entire control unit 10. Connected to the overall management unit 15 are an other vehicle data receiving unit 26 that receives traveling data of other vehicles and an own vehicle data transmitting unit 24 that transmits traveling data of the own vehicle to other vehicles. The travel data sent to and received from other vehicles includes identification information for each vehicle (for example, number plate number and identification information for emergency vehicles such as ambulances and fire engines), current position, vehicle speed, destination , Blinker information indicating blinking of the blinker, and the like are included.
[0022]
The input management unit 16 receives a signal from the operation of the switch 22a of the display unit 20 via the switch input management unit 22, and according to this, the destination setting and switching of the display screen 21A of the display unit 20 are performed as a whole. The management unit 15 is instructed.
[0023]
Next, the destination setting operation of the in-vehicle navigation device according to the first embodiment will be described with reference to FIGS. When the switch of the navigation device is turned on (S11 is Yes), the control unit 10 starts the operation. First, the destination set via the switch 22a of the display unit 20 is input (S12). Based on the destination and the current position measured by the current position measuring unit 30, the map data including the destination and the current position is read from the map information storage unit 40. Here, FIG. 7 shows an image display example displayed on the display screen 21 based on the read map data. Here, the destination is indicated by D, and the vehicle position is indicated by MI. Then, the control unit 10 selects a route from the current position to the target position (S13). At this time, the shortest route R1 is selected from a plurality of travelable routes from the vehicle position MI to the destination D.
[0024]
Subsequently, the control unit 10 transmits own vehicle travel data (own vehicle identification information, current position, route to the destination, vehicle speed, destination, turn signal information indicating blinking of the blinker) from the own vehicle data transmission unit 24. (S14). The travel data is transmitted by infrared rays. Next, other vehicle travel data (infrared vehicle identification information, current position, vehicle speed, destination, route to destination, turn signal information) by infrared rays is received via the other vehicle data receiving unit 26 (S15). ), The received content is transferred from the vehicle data transmission unit 24 (S16). That is, in the navigation apparatus of the present embodiment, the traveling data is transferred in a relay form by transferring the traveling data of other vehicles received via infrared rays.
[0025]
The transfer of the travel data will be described with reference to FIG. It is assumed that three vehicles A, B, and C are traveling on the road. First, the vehicle C sends its traveling data to the front, rear, left and right vehicles. Then, the rear vehicle B that has received the travel data from the vehicle C sends the travel data received from the vehicle C together with the travel data of the own vehicle to the front, rear, left and right vehicles. The vehicle A traveling at the end receives the traveling data of the vehicle B traveling immediately before and the vehicle C traveling further ahead, and uses it for route guidance as will be described later.
[0026]
Next, the control unit 10 processes the other vehicle data (S17). Here, based on the travel data of the other vehicle received in step 15, the position of the other vehicle traveling in the same direction as the host vehicle MI (here, the other vehicle) is displayed on the map data (display image) shown in FIG. 8) plotting the vehicle E1, E2, E3, and E4 assuming that traveling data can be received. Whether the other vehicle is traveling in the same direction as the host vehicle is determined by receiving the position of the other vehicle specified by the identification signal of the traveling data twice or more and determining the traveling direction. Alternatively, the traveling direction may be determined based on the route to the destination of another vehicle. Then, route examination processing for examining the route is executed (S30). The route examination process will be described in detail with reference to FIG. 3 showing the subroutine of the route examination process.
[0027]
First, the control unit 10 determines whether the number of other vehicles E1, E2, E3, and E4 plotted on the route R1 that is the travel route of the vehicle in the map data is so large that the smooth traffic of the vehicle is hindered. It is determined whether or not (S31). This determination is made in consideration of the road width of the route R1, the speed limit, and the like. For example, if the road width is wide at 12m on one side and the speed limit is as high as 60km, the presence of four other vehicles will not hinder smooth traffic of the host vehicle, so the judgment in step 31 is No. It becomes. On the other hand, when the road width is as narrow as 4 m and the speed limit is as low as 40 km, it is determined that smooth traffic of the host vehicle is hindered by the presence of four other vehicles (Yes in step 31).
[0028]
If step 31 is No, it is determined whether the number of vehicles that will continue to pass the same route is large (S32). Here, as shown in FIG. 9, a case will be described in which it is determined whether or not other vehicles E1, E2, E3, and E4 preceding the own vehicle MI are scheduled to pass the route R1 from their respective destinations. First, a route to be passed is estimated based on the current positions and destinations of the other vehicles E1, E2, E3, E4. Here, for example, when the other vehicles E1 and E2 are heading to the same destination D as the own vehicle MI, and the other vehicle E3 is heading to the destination passing through the route R1 although the destination is different. It is determined that the number of vehicles passing through the same route is large (S32 is Yes). On the other hand, if the other vehicles E1, E2, E4 are heading to the destination via the route R4 in the figure, it is determined that the number of vehicles passing the same route is small (No in S32). Here, the route to be passed is estimated based on the current positions and destinations of the preceding other vehicles E1, E2, E3, E4, but in order to simplify the processing in this step 32, the own vehicle MI and the destination It is also possible to determine whether the number of vehicles passing through the same route is large depending on whether or not they are the same.
[0029]
In addition, when the route from the other vehicle to the destination is received, it is determined based on the routes of the other vehicles E1, E2, E3, and E4 whether the number of vehicles scheduled to pass through the same route is large. .
[0030]
Further, when the above step 32 is No, it is next determined whether or not the traveling speed of the other vehicle on the route R1 scheduled to pass is low (S33). Here, the speeds included in the received travel data are determined for the other vehicles E1, E2, E3, and E4 shown in FIG. At this time, it is determined whether or not the speed is low in consideration of the speed limit of the traveling route R1. For example, even if the speed of the other vehicle E1 is 40 km / hour, it is determined that it is low when the speed limit is 60 km / hour, but is high when the speed limit is 40 km / hour.
[0031]
Here, if all of the above-described determinations at steps 31, 32, and 33 are No, it is determined whether a route change flag P described later is set (S36), and this route change flag P is not set. If this is the case (No in S36), the subroutine for the route examination process is terminated and the process returns to the main routine shown in FIG.
[0032]
On the other hand, if any of the determinations in steps 31, 32, and 33 is Yes, the route is changed (S34). Here, the route R1 that is the shortest distance to the destination D shown in FIG. 8 is changed to the route R2 that is the next shortest distance. Then, a route change flag P indicating that the route has been changed is set (S35), and the process returns to step 31 to determine whether the number of vehicles is large for the route R2, and then the route R2 is scheduled to pass. It is determined whether the number of vehicles is large (S32). Finally, it is determined whether the traveling speed on the route R2 is low (S33). If any of the determinations in steps 31, 32, and 33 is Yes, the route to be further traveled is changed to the route R3 having the shortest distance to the destination D (S34). On the other hand, if all of the determinations at steps 31, 32, and 33 are No, it is determined whether the route change flag P is set (S36). Here, as described above, the route change flag P is set. (S36 is Yes), the driver is instructed to change the route (S37). Here, the changed route R2 on the display image shown in FIG. 8 displayed on the display screen 21A of the display unit 20 is color-coded and indicated (not shown), and “change route” is given from the speaker 21B. "The voice message" Then, the route change flag P is cleared (S38), the route examination processing subroutine is terminated, and the process returns to the main routine shown in FIG.
[0033]
Subsequently, the control unit 10 determines whether information indicating lighting of the hazard is included in the turn signal information included in the travel data received from the other vehicle (S19). Here, when the information which shows lighting of a hazard is contained (S19 is Yes), it transfers to a hazard process (S40). Here, this hazard process will be described with reference to FIG. 4 showing a subroutine of the hazard process.
[0034]
First, when the control unit 10 receives travel data including information indicating the lighting of the hazard from another vehicle, the other vehicle that is lighting the hazard is on the traveling route of the own vehicle MI (here, the route R1). It is determined whether the vehicle is related to the vehicle MI by determining whether the vehicle is traveling or stopped (S41). In other words, if the other vehicle with the hazard lit is the other vehicle E8 traveling on the route 2 in FIG. 10, it is determined that it is not related to the own vehicle MI (S41 is No), and the hazard processing is performed. finish. On the other hand, if the other vehicle with the hazard lit is the other vehicle E5 traveling on route 1 in FIG. 10, it is determined that it is related to the own vehicle MI (Yes in S41), and the hazard is given to the driver. Information about the presence of other vehicles that are lit is provided (S42). Here, a voice message “There is a vehicle whose hazard is lit 700 m ahead” is sent from the speaker 21B to call attention, and the other vehicle is specified on the display image of the display screen 21A. And it is judged whether it is necessary to change a route with the vehicle which has lighted this hazard (S43). Here, as shown in the figure, when only one vehicle E5 lights up the hazard, it is determined that there is no need to change the route (No in S43). On the other hand, when two of the other vehicles E6 and E7 shown in the figure are lit, an accident or traffic jam is expected, so the determination in step 43 regarding whether or not the route needs to be changed is Yes. As in step 34 shown in FIG. 3, the route is changed from the route R1 to the route R2 (S44), the route change flag P indicating that the route has been changed is set (S45), and the hazard process is terminated. Return to the main routine shown in FIG.
[0035]
The control unit 10 subsequently determines whether or not identification information indicating an emergency vehicle such as an ambulance or fire engine is included in the vehicle identification information of the travel data received from another vehicle (S20). Here, when the identification information which shows an emergency vehicle is contained (S20 is Yes), it transfers to an emergency vehicle process (S50). Here, the emergency vehicle processing will be described with reference to FIG. 5 showing a subroutine of the emergency vehicle processing.
[0036]
First, when the control unit 10 receives travel data including emergency vehicle information, the other vehicle (emergency vehicle) that transmitted the travel data travels on the travel route of the own vehicle MI (here, the route R1). It is determined whether the vehicle is related to the host vehicle MI by determining whether the vehicle is traveling or stopped (S51). That is, when the other vehicle (emergency vehicle) is the other vehicle I2 traveling leftward on the route R4 in FIG. 11, it is determined that it is not related to the own vehicle MI (No in S51), and the emergency vehicle The process ends. On the other hand, when the other vehicle (emergency vehicle) is the emergency vehicle I1 in FIG. 11 approaching from the right side with respect to the traveling direction of the own vehicle, it is determined that the vehicle is related (S51 is Yes), and the driver is urgent. Information about the approach of the vehicle is provided to call attention (S52). Here, a voice message “An emergency vehicle is coming from the right side to the intersection 200 m ahead” is played from the speaker 21B, and the emergency vehicle is specified on the display image of the display screen 21A. And it is judged whether a route needs to be changed by this emergency vehicle (S53). Here, as shown in the figure, when there is only one emergency vehicle I1, it is determined that there is no need to change the route (No in S53). On the other hand, as shown in FIG. 11, in the route R1, when the three emergency vehicles I3, I4, and I5 are stopped, there is a risk of a fire, an accident, etc. and a traffic jam is expected. And the determination in step 53 is Yes, the route is changed from the route R1 to the route R2 in the same manner as in step 34 shown in FIG. 3 (S54), and the route change flag P indicating that the route has been changed (S55), and the emergency vehicle processing is terminated.
[0037]
By repeating the above-mentioned process, in addition to actual traffic jams, forecasting future accidents and traffic jams based on driving data from other vehicles, avoiding routes that may cause such situations. And get involved in an accident. That is, in the above-described embodiment, it is possible to prevent an accident from occurring by detecting the danger in advance. In addition, since the driver can avoid being involved in a traffic jam, the driver can arrive at the destination in the shortest time. According to the in-vehicle navigation system of the present embodiment, the traffic system as a whole can be relieved of traffic, smoother logistics, less energy consumption, and lower without providing infrastructure such as provision of traffic jam information by broadcasting. Pollution can be realized.
[0038]
In the above-described embodiment, the traveling data includes the identification information of the own vehicle, the current position, the vehicle speed, the destination, and the blinker information. In addition, information such as accelerator, brake, steering angle, etc. is included as travel data to detect the dangers of braking, lane change, stopping, etc. of two or more vehicles that are not visible, and inform the driver of this. It can also be configured as follows. On the basis of this, it is also possible to set the automatic transmission gear to one stage, to automatically reduce the vehicle speed, or to increase the inter-vehicle distance. Furthermore, it can be configured to indicate an appropriate speed to the intersection based on the information of the vehicle stopped by the signal.
[0039]
In the above-described embodiment, infrared rays are used for communication between vehicles. However, other rays such as ultraviolet rays or ultrasonic waves can be used, and a weak range that can reach only a limited range. By using radio waves, the vehicle can be directly transmitted and received within a limited range without transferring the travel data as in step 16 of FIG. 2 described above.
[0040]
【effect】
As described above, in the in-vehicle navigation system according to claim 1, the number of other vehicles existing on the set route is as follows.Whether it is more than a predetermined numberIf it is determined that there are many other vehicles, the route is changed, so it is possible to set a route while avoiding a route with many crowded vehicles, and reach the destination in the shortest time be able to.
[0041]
In the in-vehicle navigation system according to claim 2 or 3, the number of other vehicles scheduled to travel on the set route isWhether it is more than a predetermined numberIf it is determined that there are many, the route is changed, so that it is possible to set a route while avoiding a route that is expected to be congested, and the destination can be reached in the shortest time.
[0042]
Furthermore, in the vehicle-mounted navigation system according to claim 4, the driver lights the hazard in order to receive the position of the other vehicle whose hazard is lit and to prompt the driver to pay attention to the other vehicle. By knowing the vehicle before viewing, you can drive safely.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an in-vehicle navigation device according to an embodiment of the present invention.
FIG. 2 is a flowchart showing a main routine of the navigation device according to the first embodiment.
FIG. 3 is a flowchart showing a subroutine of route examination processing in the flowchart shown in FIG. 2;
4 is a flowchart showing a hazard processing subroutine of the flowchart shown in FIG. 2; FIG.
FIG. 5 is a flowchart showing a subroutine of emergency vehicle processing in the flowchart shown in FIG. 2;
FIG. 6 is an explanatory diagram showing transfer of travel data by the navigation device of the present embodiment.
FIG. 7 is an explanatory diagram illustrating an example of a display image by the navigation device according to the present embodiment.
FIG. 8 is an explanatory diagram illustrating an example of a display image by the navigation device according to the present embodiment.
FIG. 9 is an explanatory diagram illustrating an example of a display image by the navigation device according to the present embodiment.
FIG. 10 is an explanatory diagram illustrating an example of a display image by the navigation device according to the present embodiment.
FIG. 11 is an explanatory diagram illustrating an example of a display image by the navigation device according to the present embodiment.
[Explanation of symbols]
10 Control unit
15 General Management Department
20 display
24 Vehicle data transmission part
26 Other vehicle data receiver
30 Current position measurement unit
40 Map information storage

Claims (4)

Destination setting device for setting a destination, positioning device for positioning the own vehicle position, another vehicle position receiving device for receiving position information of another vehicle transmitted from another vehicle, and map information storage for holding map information Unit, a map information reading device that reads map information from the map information storage unit, map information read by the map information reading device, and a current position measured by the positioning device, and set by a destination setting device An in-vehicle navigation system comprising a route setting device for setting a route to a destination,
Based on the position information of the other vehicle received by the other vehicle position receiving device, the number of other vehicles traveling on the set route is estimated, and it is determined whether or not the estimated number of other vehicles is a predetermined number or more. Other vehicle number judgment means to
An in-vehicle navigation system, wherein the route set by the route setting device is changed when the number of other vehicles is determined to be greater than or equal to a predetermined number. The other vehicle position receiving device further receives destination information of the other vehicle,
The other vehicle number determination means estimates the number of other vehicles traveling on the set route based on the received position information and destination information of the other vehicle, and the estimated number of other vehicles is a predetermined number. The in-vehicle navigation system according to claim 1, wherein it is determined whether or not the above is true. The other vehicle position receiving device further receives a route to the destination of the other vehicle,
The other vehicle number judging means estimates the number of other vehicles traveling on the set route based on the received other vehicle position information and the route to the destination of the other vehicle, and The in-vehicle navigation system according to claim 1, wherein it is determined whether or not the number is a predetermined number or more. Destination setting device for setting destination, positioning device for positioning own vehicle position, other vehicle position receiving device for receiving lighting of other vehicle position and hazard of other vehicle, and map information storage unit for holding map information And a map information reading device that reads map information from the map information storage unit, map information read by the map information reading device, and a current position measured by the positioning device, and set by a destination setting device An in-vehicle navigation system comprising a route setting device for setting a route to a destination,
Based on the position of the other vehicle lighting the hazard received by the other vehicle position receiving device, it is determined whether there is another vehicle lighting the hazard on the route set by the route setting device. Other vehicle judgment means,
An in-vehicle navigation system comprising: an alerting means for urging the driver to pay attention to another vehicle whose hazard is lit as determined by the other vehicle determining means.

Images