JP3279009B2 - Route guidance device for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device provided inside a vehicle for notifying a passenger of information sent from the outside of the vehicle, and for controlling the vehicle along a route to a preset destination. The present invention relates to a vehicle route guidance device for guiding.

[0002]

2. Description of the Related Art In recent years, the position of a vehicle has been measured by receiving radio waves from artificial satellites, and the position has been collated with map information mounted on the vehicle. A so-called GPS navigation system that displays a vehicle position and notifies the driver of the position is provided for general demand.

In this system, the map information stored in advance in a device mounted on the host vehicle is information at the time of storage, not information at the time of actual display. In this system, the information at the actual time is only the position of the host vehicle. Therefore, passengers have to rely on external information such as traffic congestion display signs on the Tokyo Metropolitan Expressway and traffic information on radio broadcasting for information that changes every moment, such as road regulation and traffic congestion information due to accidents. In addition, there are cases where map information mounted on a vehicle does not match the actual one due to road repair work or the like.

On the other hand, a system has been developed in which information is transmitted from a base station or a beacon installed on the side of a road, the information is received by a receiving device of a vehicle, and the passenger is notified. For example, a system has been developed that transmits traffic congestion information, regulation information, accident information, and the like of the entire Metropolitan Expressway from a base station on a metropolitan expressway in a city center and displays the information on a display device mounted on a vehicle. A display such as a road information display plate which is currently installed at more than a dozen locations on the Metropolitan Expressway can be displayed on a display device in the vehicle. According to this, there is no case where the contents cannot be sufficiently checked by passing through the conventional display board installed above or on the side of the road, and the information can be checked when the passenger desires.

When information is transmitted by radio waves or light from a beacon installed on the side of the road, passengers can transmit more information by transmitting important information within a range where the radio waves and the like can reach. Information can be obtained. For example, if information on an approaching intersection is displayed, the content can be confirmed even after passing through a conventional road display board, similarly to the above-described traffic congestion information. Further, it is possible to provide more useful information to the passenger by, for example, creating and displaying information on the time required to reach a predetermined point based on the current road conditions. As described above, by notifying the current information, the passenger can perform route selection or the like corresponding to this situation.

Further, a destination point is inputted, a route that can reach the destination point in the shortest time based on the information sent from the outside is searched for, and a route for guiding the own vehicle along the searched route is provided. Guidance devices have been developed. Japanese Patent Application Laid-Open No. Sho 62-60100 discloses a route guidance device that calculates the required time based on the degree of congestion and the distance obtained from the outside, and notifies the passenger of the shortest required time to the destination as the optimal route. Has been described.

In recent years, social facilities have been improved, and it is possible to transmit the time (travel time) required to pass a predetermined section (link) of a road as external information. Using this travel time, the travel time to the destination can be calculated directly, and the search for the shortest time route can be easily performed.

[0008]

However, the link travel time included in the external information is the time required when the vehicle travels straight on the link and passes therethrough. Time such as waiting for is not taken into account. Further, the link travel time sent as external information may be incorrect information due to a measurement error, a transmission error, a reception error, or the like. Therefore, there is a problem that the calculated travel time to the destination is not always accurate.

[0009] In addition, the link travel time is limited to the target link. If a route search is performed based only on this information, the selectable route is naturally limited to the link to which the travel time information is added. . Therefore, even if there is a route that can be reached in a shorter time, if there is a link to which no link travel time is given, the route is not searched. Therefore, there has been a problem that an undesired route may be searched more than necessary, or a route may not be searched in the worst case.

In order to solve this problem, it is necessary to estimate a link travel time from other information for a link having no link travel time information. The above publication discloses an apparatus for calculating a required link time (travel time) from the degree of traffic congestion and a distance (link length), but does not take into account the time required for right turn, left turn, and the like. Therefore, there was a problem that an accurate travel time could not be calculated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems. The present invention corrects a received link travel time under a predetermined condition to obtain a more accurate link travel time. It is an object of the present invention to provide a vehicle route guidance device that can search for a more appropriate shortest travel time route by estimating a link to which a travel time has not been given.

[0012]

Means for Solving the Problems In order to achieve the above object, there is provided means for correcting the received link travel time under predetermined conditions. Also, for a link to which a link travel time is not given, an estimating means for estimating the travel time from other information is provided.

More specifically, according to the first aspect of the present invention, a speed calculating means for calculating a required speed of the link from a link travel time and a length of the link, and a case where the required speed is a predetermined value or more. Has a rejection instruction means that does not use the link travel time when searching for a route.

Further, in the invention according to claim 2,
Speed calculation means for calculating a required speed of the link from the link travel time and the length of the link; a congestion degree detection means for detecting a congestion degree included in the external information and representing a degree of congestion as an average vehicle speed; If the required speed and the congestion degree are compared and they do not match, a rejection instructing unit that does not use the link travel time when searching for a route is provided.

Further, in the invention according to claim 3,
Congestion degree detection means included in the external information and detecting the degree of congestion represented by the average vehicle speed of the degree of congestion, required time calculation means for calculating the required time to pass through the link from the congestion degree and the length of the link, When the required time and the travel time of the link are compared and they do not match, a rejection instructing unit that does not use the link travel time when searching for a route is provided.

Further, in the invention according to claim 4,
There is a right / left turn correcting means for correcting the link travel time based on the information on the right / left turn of the intersection. In addition, oncoming lanes
Traffic and / or traffic at intersections
Right and left turn time changing means for changing the time required for turning right and left
have.

[0017]

[0018]

Further, in the fifth aspect of the present invention,
While traveling on a toll road, there is a toll road priority correction means for correcting the link travel time so that the toll road is prioritized.

In the invention according to claim 6 ,
Small link setting means for further dividing the link to which the link travel time information is added into a plurality of small links; and a small link travel time calculation for calculating the small link travel time by proportionally distributing the link travel time according to the distance of the small link. Means.

Further, in the invention according to claim 7 ,
Small link setting means for further dividing the link to which the link travel time information is added into a plurality of small links; and calculating the small link travel time by reducing the signal waiting time by proportionally distributing the link travel time according to the distance of the small link. It has a small link travel time calculation means.

Further, in the invention according to claim 8 ,
A link equivalent length calculating means for calculating a link equivalent length from the right and left turn equivalent length representing the time required for turning right and left by a road length and an actual link length, and an average vehicle speed of a link from congestion degree information included in external information. An average vehicle speed calculating means and a link travel time calculating means for calculating a link travel time from the link equivalent length and the average vehicle speed for a link whose link travel time cannot be obtained from external information.

Further, in the invention according to claim 9 ,
Link equivalent length calculating means for calculating the link equivalent length from the right and left turn equivalent lengths representing the time required for right and left turns by the road length and the actual link length, and storage means in which the average vehicle speed for each time zone for each link is stored in advance. Link travel time calculating means for calculating a link travel time from the link equivalent length and the average vehicle speed of the storage means for a link whose link travel time cannot be obtained from external information.

According to the tenth aspect of the present invention, the actual length of the right / left turn corresponding to the time required for turning right and left is represented by the road length and the equivalent length of the traffic regulation corresponding to the time required for the traffic regulation is represented by the road length. Link equivalent length calculation means for calculating the link equivalent length from the length, average vehicle speed calculation means for calculating the average vehicle speed of the link from the congestion degree information included in the external information, and link travel time for links for which the link travel time was not obtained from the external information. On the other hand, there is provided a link travel time calculating means for calculating a link travel time from the link equivalent length and the average vehicle speed.

In the invention according to the eleventh aspect , the actual time required for the right and left turns is indicated by the road length and the equivalent length of the right and left turns is represented by the road length, and the required time required for the traffic regulation is represented by the road length and the equivalent length of the traffic regulation. Link equivalent length calculating means for calculating the link equivalent length from the length, storage means in which an average vehicle speed for each time zone for each link is stored in advance, and the link equivalent for the link for which the link travel time was not obtained from external information. A link travel time calculating means for calculating a link travel time from the length and the average vehicle speed in the storage means.

Further, the invention described in claim 12 provides
12. The vehicle route guidance device according to any one of 8 to 11 , further comprising a road type correction unit that corrects the link travel time based on the road type of the link.

[0027] Further, the invention described in claim 13 is the present invention.
13. The vehicle route guidance device according to any one of 8 to 12 , further comprising a road width correction unit that corrects the link travel time based on the road width of the link.

The invention according to claim 14 is the invention
14. The vehicle route guidance device according to any one of 8 to 13 , further comprising a lane regulation correcting unit that corrects the link travel time based on link lane regulation information.

In the invention according to the fifteenth aspect , the storage means in which the average vehicle speed for each time zone for each link is stored in advance, and the average vehicle speed for each time zone is stored in a link having temporary traffic restriction information. And a passage time calculating means for calculating a passage time of the link based on the link length, a waiting time calculation means for calculating a waiting time until the suspension of traffic regulation is released, and a communication time of the link from the passage time and the waiting time. Travel time calculating means for calculating the travel time.

Further, in the invention according to claim 16 , for a link for which the link travel time information cannot be obtained, there is provided travel time estimating means for estimating the travel time of the link from the travel time of a peripheral link. ing.

[0031] The invention described in claim 17 is the same as the invention.
In the vehicle route guidance device according to Item 16 , the travel time estimating means estimates travel time based on travel times of links before and after the link.

[0032] The invention described in claim 18 is the same as the invention.
In the vehicle route guidance device according to Item 16 , the travel time estimating means estimates the travel time based on the travel times of the left and right links parallel to the link.

[0033] Further, the invention described in claim 19 provides the invention
16. The vehicle route guidance device according to Item 16 , wherein the travel time estimating means estimates a link travel time based on an average degree of congestion in a secondary mesh including the link or a mesh obtained by further subdividing the secondary mesh. is there.

[0034] In the invention according to the twentieth aspect, there is provided travel time calculating means for calculating a link travel time for a link for which the link travel time information was not obtained based on information at the time of previous reception. ing.

In the invention according to the twenty- first aspect, a travel time estimating means for estimating a link travel time for a link for which the link travel time information was not obtained based on information at the time of receiving a plurality of times in the past. have.

[0036]

In the invention according to claim 22 , the driving environment evaluation means for evaluating the easiness of driving based on the traveling route and the surrounding conditions, and it is determined that the driving is most easy based on the driving environment evaluation. Route searching means for calculating the route obtained as the optimum route.

According to a twenty- third aspect of the present invention, in the vehicle route guidance apparatus according to any one of the first to third aspects, the shortest route searching means for searching for the shortest route, and the shortest route and the optimum route are determined. Comparison display means for comparing and displaying.

[0039]

The present invention has the above-described configuration, and it is possible to search for an optimum route using a more accurate link travel time. Also, a link to which no link travel time information is assigned can be set as a search target by estimating the link travel time information.

More specifically, according to the first aspect of the present invention, when the speed of passing through the link is equal to or higher than a predetermined value, it is determined that the link travel time is incorrect for some reason, and the data is employed as data. do not do.

According to the second aspect of the present invention,
If the vehicle speed determined from the received link travel time does not match the vehicle speed determined from the degree of congestion, it is determined that the travel time of the link is incorrect for some reason and adopted as data. do not do.

According to the third aspect of the present invention,
If the received link travel time does not match the required transit time determined from the degree of traffic congestion, it is determined that the travel time of the link is incorrect for some reason and is not adopted as data.

According to the fourth aspect of the present invention,
The received link travel time is corrected based on the presence or absence of a right or left turn. That is, in consideration of, for example, the time of waiting for a right turn, a route search is performed using the received link travel time plus the time of waiting for a right turn. Crossing oncoming lane
Change the time required to turn left or right in consideration of traffic congestion
Thus, the link travel time is corrected.

[0044]

[0045]

Further, in the fifth aspect of the present invention,
When traveling on a toll road, the link travel time is corrected so as to preferentially pass through the toll road.

In the invention according to claim 6 ,
A travel time proportional to the distance is given to a small link obtained by further subdividing a link transmitted from the outside.

Further, in the invention according to claim 7 ,
A travel time is allocated in proportion to the distance to a small link obtained by further subdividing a link transmitted from the outside, and a travel time in which a signal waiting time is reduced from the travel time is given.

In the invention according to claim 8 ,
For a link to which no travel time has been given, the travel time of the link is estimated from the right / left turn information and the degree of congestion included in the external information.

According to the ninth aspect of the present invention,
For a link to which no travel time has been given, the travel time of the link is estimated from the right / left turn information and the average vehicle speed for each time zone stored in advance.

According to the tenth aspect of the present invention, for a link to which no travel time has been given, the travel time of the link is estimated from the right / left turn information, the traffic regulation information, and the degree of congestion included in the external information. I do.

According to the eleventh aspect of the present invention, for a link to which no travel time has been given, the travel time of the link is determined from the right / left turn information, the traffic regulation information, and the hourly average vehicle speed stored in advance. Is estimated.

The twelfth aspect of the present invention provides
In the invention according to any one of 8 to 11, the link travel time can be further corrected according to the type of road.

Further, the invention described in claim 13 is the same as the invention.
In the invention described in any one of Items 8 to 12, the link travel time can be further corrected by the width of the road.

The invention according to claim 14 is the invention
In the invention according to any one of Items 8 to 13, the link travel time can be further corrected based on the lane regulation information.

In the invention according to the fifteenth aspect , the link travel time is corrected by adding the waiting time until the suspension of traffic restriction is canceled to the link having the temporary suspension of traffic restriction.

In the invention according to claim 16 , for a link for which travel time information has not been obtained, the travel time of the link is estimated from the travel times of the links around the link.

Further, the invention described in claim 17 is the same as the invention.
In the invention described in Item 16 , the travel time of the link is estimated from the travel times of the links before and after the link.

Further, the invention described in claim 18 is the invention
In the invention described in Item 16 , the travel time of the link is estimated from the travel times of the left and right links parallel to the link.

Further, the invention according to claim 19 provides
In the invention described in Item 16 , the link travel time is estimated based on the average degree of congestion in the secondary mesh including the link or in the mesh obtained by further subdividing the secondary mesh.

According to the twentieth aspect of the present invention, a link travel time is calculated for a link for which link travel time information was not obtained based on information at the time of previous reception.

In the invention according to claim 21 , for a link for which link travel time information has not been obtained, the link travel time is calculated based on information at the time of receiving a plurality of times in the past.

[0063]

Further, in the invention according to claim 22 , easiness of driving is evaluated based on the traveling route and the surrounding conditions, and a route with a small burden on the passenger, particularly the driver, is searched.

In the invention according to claim 23 , the route searched by the means described in any one of the above-mentioned claims is compared with a route having the shortest traveling distance and displayed. Can be.

[0066]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments according to the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a vehicle external information notification device according to this embodiment. GPS antenna 10 and GPS receiver 1 that constitute a GPS navigation system
2, various sensors such as a vehicle speed sensor 14, a steering sensor 16, a geomagnetic sensor 18, and a distance sensor 20, and a control unit 22. G in the GPS receiver 12
The radio wave received from the geodesic satellite in the satellite orbit received by the PS antenna 10 is received. The control unit 22 calculates the latitude and longitude of the current position of the vehicle based on the direction of the received radio wave.
This device basically employs a so-called self-contained navigation system that calculates a current position by integrating detection values from a departure point by sensors such as a vehicle speed sensor 14, a steering sensor 16, a geomagnetic sensor 18, and a distance sensor 20. Have been. However, in order to further improve the detection accuracy of the current position, the correction is performed based on the current position of the own vehicle calculated based on the radio wave from the geodetic satellite.

The specific operation of each sensor is as follows. First, the vehicle speed is detected by the vehicle speed sensor 14 to calculate how much the own vehicle has moved in a predetermined time. This distance can also be calculated by the distance sensor 20. The steering sensor 16 and the geomagnetic sensor 18 can calculate how much the own vehicle has changed the traveling direction. The detection of the amount of change in the traveling direction may be performed by a gyro system. Then, the latitude and longitude detected by these sensors are compared with the map information stored in the map information storage unit 24, and the position of the own vehicle on the map is calculated by the control unit 22. Then, the map information and the position of the host vehicle are superimposed and displayed on the display unit 26 provided near the driver's seat to notify the passenger. Further, the detected position of the host vehicle is always compared with the map information, and it is determined whether the position on the map is an appropriate position. For example, if there is no road at the place where the vehicle is currently traveling and there is a road parallel to the traveling locus of the vehicle, the vehicle position is shifted and the current position is corrected to be on the road. The position detection accuracy detected by each of the above-described sensors is compensated by such correction called map matching.

Further, in the present apparatus, a destination point is set in advance, and a route to the destination point is stored, thereby guiding a route to be selected in front of an intersection to be turned. Guidance can be provided along the route. When the destination is input from the input unit 28, the control unit 22 searches for a route from the current location measured by the GPS to the destination, and the searched route is stored in the route storage unit 30. Then, the route guidance is performed by comparing the route stored during the actual traveling with the position of the own vehicle. The route guidance is performed, for example, by displaying a map around the intersection on the display unit 26 and indicating the route with an arrow or the like in front of the intersection where a right or left turn is to be performed. indicate. further,
In the case of this apparatus, guidance by voice is also performed by the voice generation unit 32 in addition to the display. For example, when approaching an intersection to make a right turn, a voice message such as "The next intersection is a right turn." If the notification is made by voice, the driver can select the set route without looking at the display on the display unit 26, so that the driver does not need to turn his / her line of sight from the front.

The functions described above are implemented in the map information storage unit 24.
The operation is performed based on the information stored by the computer, and the information at the present time is not taken into account. Therefore, the searched route may not be able to actually pass due to traffic regulations such as road construction. In addition, there is a section where traffic is congested in a part of the searched route, and there may be a case where actually selecting another route reaches the destination in a short time. Such inconvenience is caused by the fact that the current information is only the position of the vehicle and does not take into account the current traffic conditions of the road such as traffic jams and regulations.

In the present apparatus, such information at the present time is received from the outside by a method described later and is used as a determination factor for path selection and the like. At present, as a method of transmitting the current traffic situation and the like from the outside to each vehicle, a method by FM multiplex broadcasting, a method of transmitting radio waves or light from a beacon provided on the side of the road, and the like are currently partially used. I have.

The present apparatus comprises an FM multiplex receiver 34 for receiving the above-mentioned FM multiplex broadcast and a beacon receiver 36 for receiving radio waves from a beacon as means for receiving external information.
It has.

The FM multiplex receiver 34 has an FM antenna 38
Receive the FM wave received by the. The information on the FM multiplex is, for example, traffic congestion on roads and regulation information. In addition, the beacon receiver 36 receives and receives a radio wave from a beacon transmission source provided on the side of the road by the beacon antenna 40. Beacons are suitable for transmitting information over a relatively small area. By utilizing this, a beacon source is installed at a predetermined position before a specific intersection,
The information specific to this intersection is transmitted. The information peculiar to the intersection is, for example, a destination display for each branching direction of the intersection, which is conventionally displayed as a signboard in front of the intersection, and a required time (travel time) from the corresponding intersection to the displayed destination. is there. On the other hand, the aforementioned FM multiplex wave is suitable for transmitting information over a wide area, and information is transmitted from a base station. The information content includes, for example, traffic congestion information on the entire Metropolitan Expressway, regulation information on accidents and falling objects, and other messages from the road manager. Of course, it is also possible to transmit congestion information, regulation information, and the like transmitted by the FM multiplex wave using a beacon.

As described above, information received by the FM multiplex receiver 34 and the beacon receiver 36 is temporarily stored,
It is displayed on the display unit 26 after the display instruction is given. This display instruction is issued, for example, after reception is completed or after it is detected that the vehicle has passed just below the beacon transmission source. Further, it may be after a predetermined distance has elapsed from the reception or after a predetermined time has elapsed. Further, it is also preferable that the display is made by a passenger giving an instruction from the input unit 28. In such a case, the display is performed only when the passenger requests it, so that the external information can be prevented from being interrupted when the passenger is looking at another screen.

As described above, in the present apparatus, the current road conditions from the outside, particularly the roads (links) between predetermined intersections
When the required transit time (travel time) for each is transmitted, a route that minimizes the total travel time of the link to the destination is searched for, and route guidance is performed along this route. Such a method of route search and route guidance is called dynamic route guidance, and the route guidance according to the traffic situation at that time is compared with the case where the route guidance is performed using only the previously stored map information. Can be performed.
That is, it is possible to perform guidance along a route that can reach the destination in a shorter time even in a long circuit.

However, the received link travel time may differ from the actual required time for various reasons.
For example, it is conceivable that the traffic condition data on each link collected for calculating the travel time includes an error or a detection error occurs. In addition, correct information may not be received at the time of information transmission due to mixing of noise or the like. Furthermore, the link travel time is calculated based on the fact that the vehicle travels straight at the intersection at the end of the link, and does not take into account the time required for turning right or left. Furthermore, when the link to which the link travel time is assigned is limited, the link to which the link travel time is not assigned is not a search target. Therefore, even if there is actually a more preferable route, it cannot be searched.

The present apparatus has various means to cope with these problems, and these will be described below in order.

In FIG. 1, the control unit 22 includes a speed calculation unit 42, a rejection instruction unit 44, and a congestion degree detection unit 46. The speed calculator 42 calculates the speed required to pass through the link based on the received link travel time. That is, the average speed of the link time can be calculated by dividing the link length stored in the map information storage unit by the link travel time. If the calculated speed is equal to or greater than a predetermined value that cannot be achieved in practice, it is determined that there is some error in the link travel time received as described above, and the rejection instruction unit 44 transmits this information to the route. Instruct them not to be employed in the search. The predetermined value, for example, a highway when it exceeds 1 0 0 km / h, the instruction not to adopt the travel time information about the link.

Further, even if the speed is within the above-mentioned predetermined value, the link travel time is not adopted even if the speed does not match the information other than the link travel time information. Specifically, the congestion degree detection unit 46 detects the congestion information included in the external information, and obtains the average speed of the link from the detected congestion information. For example, on the Tokyo Metropolitan Expressway, the speed of the section is 0 to 20 km / h in the case of "congestion", and 2 in the case of "congestion".
The vehicle speed in this section is determined from 0 to 40 km / h, and 40 km / h or more in the case of “normal”.
Then, it is compared whether the vehicle speed calculated from the link travel time and the link length falls within the speed range. That is, the vehicle speed obtained in the section of “congestion” is 20
If the distance does not fall within the range of ４０40 km / h, the link travel time at this time is not adopted.

In the above case, the average vehicle speed was calculated from the link travel time and compared with the degree of congestion. However, conversely, the time required to pass through the link is determined from the degree of traffic congestion,
It is also preferable to compare this with the received link travel time. FIG. 2 is a diagram showing the configuration of the device in this case,
The required time for passing through this link is calculated by the required time calculating unit 48 from the speed indicating the congestion detected by the congestion degree detecting unit 46 and the link length stored in the map information storage unit 24. And
The calculated required time is compared with the received travel time. If the travel time does not match, the rejection instruction unit 44 rejects the link travel time information.

Next, correction for improving the accuracy of the adopted link travel time will be described. The transmitted link travel time is created based on the time required to pass straight through the link. Therefore, the time required for making a left turn, a right turn, or a U-turn at the intersection at the end of the link is not considered. For example, in the case of a right turn, it is necessary to wait for a vehicle in the opposite lane to be cut off and then turn right. In a lane dedicated to a right turn or the like, the number of times of signal waiting may be greater than in a straight-ahead vehicle. In this way, when making a right turn at the link end,
It often takes extra time than when going straight ahead, so it is necessary to correct the received link travel time. In the present apparatus, this correction amount is obtained by converting an extra time required for an operation such as a right turn into a distance and adding it to the link length. Hereinafter, the correction amount converted into the distance is referred to as “cost”. For example, the correction amount to be added for a right turn is “right turn cost”. Each cost is as shown in FIG. 3, for example. For example, when performing a route search, the calculation is performed on the assumption that the distance of a link that turns right at the end thereof is 150 m longer than the actual distance. That is, if the required travel time of this link is T, the travel time received is A, the link length is A, and the cost of turning right and left is B,

(Equation 1) Becomes The right / left turn correction unit 50 in FIG. 4 performs such correction.

The above case is a case where the right / left turn cost is a fixed value, but the right / left turn cost is actually changed depending on the traffic volume of the oncoming lane or the crossing road. In the case of the present apparatus, a right / left turn time changing unit 52 is provided to cope with this. In the case of the right turn cost, the change unit 52 calculates the cost as a function of the speed of the vehicle entering the intersection of the oncoming lane and the speed of the right turn lane exiting the intersection.

Next, a case where the link travel time is corrected based on the frequency of the route selected by the driver in the past will be described. FIG. 5 shows the configuration of this device. In this case, near the home and near the frequently used parking lot, the history of the route that the driver has passed is detected, and the selection frequency calculation unit 52 calculates the selection frequency.

The home or the most frequently used parking lot is determined by storing the position when the ignition key is turned on or off, so that the most frequently used location is the home and the next most frequently used parking lot is determined. judge. The detection of this position
It may be performed by GPS, and the above-described vehicle speed sensor 1
4 or the position calculated by the navigation system using the geomagnetic sensor 18 or the like. The determination of the vicinity of the home or the like is performed based on the number of passing branch points from the home or the like, and until the number reaches a predetermined number, the vicinity of the home or the like is determined. Then, the driving frequency is stored for each link in this range. Then, in the selection frequency correction unit 56,
By multiplying the travel time by a coefficient such as 0.5 for a link having a high frequency, the required time of the link is apparently shortened to increase the possibility that the link becomes a guide route. The coefficient is changed according to the frequency, and is set so that the more frequently the route is searched, the more the route is searched. However, a lower limit value is set for this coefficient, and the coefficient is set so that an extremely extreme result is not obtained.

The reason that the travel time is corrected according to the frequency in the vicinity of the home or the like in the present apparatus is that the driver tends to travel on a road to which the driver is accustomed in the vicinity of the home or the like. This is because even if the road is narrow and difficult to pass, the user tends to select this road when he is used to it, and this is reflected.

Next, a description will be given of a device for searching for a route which can be continued on a toll road when possible. As shown in FIG. 6, in the case of the present apparatus, a toll road priority correction unit 58 is provided. The correction unit 58 multiplies the link travel time of the toll road by, for example, a coefficient of 0.8 to increase the possibility that the toll road is searched. By giving priority to toll roads, it is possible to prevent a person from once leaving a general road and then re-entering the toll road due to a small traffic congestion on the toll road, etc., and preventing paying a road toll twice.

The apparatus which corrects the received link travel time so that route guidance according to the situation is performed has been described above. However, the link travel time is not given or given for some reason. A device for estimating a travel time for a link that has not been set will be described.

The link transmitted as external information connects relatively large intersections. However, in the case of performing actual route guidance, it is desirable to target intersections and roads smaller than the intersection. Therefore,
Even for a link to which a link travel time is assigned, it is desirable to calculate a travel time to an intersection in the middle of the link.

The apparatus shown in FIG. 7 has a small link setting section 60 for setting small links obtained by further dividing links corresponding to external information, and further calculates small links for calculating travel times of these small links. The travel time calculator 62 is provided. FIG. 8 shows the relationship between small links. The link A between the intersections I1 and I2 is further divided into three small links A1, A2 and A3. The travel time is most simply calculated in proportion to the length of the small link. In order to improve the accuracy, the link travel time includes the signal waiting time at the intersection I3 in the link, and therefore, the small link travel time needs to exclude the signal waiting time at the terminal intersection of the small link. Therefore,
If the travel time T1 of the small link A1 is the travel time T of the received link A and the signal waiting time T0,

(Equation 2) Is calculated as

Next, FIG. 9 is a diagram showing a configuration of an apparatus for estimating a travel time for a link for which a link travel time was not obtained as external information. Link equivalent length calculation unit 64
Calculates the link equivalent length from the actual link length, right / left turn cost, and traffic regulation cost. As described above, the right / left turn cost is the time required to make a right / left turn by distance, and the traffic regulation cost is the cost associated with static regulation such as one-way traffic and no right turn. Infinite. If the link length is A, the right / left turn cost is B, and the traffic regulation cost is C, the link equivalent length is
A + B + C.

The average vehicle speed calculation section 66 calculates the average vehicle speed V from the degree of congestion included in the external information. If the congestion degree is defined in relation to the average vehicle speed at that time, as in the case of the aforementioned Tokyo Metropolitan Expressway, this vehicle speed may be used. If the traffic speed is simply indicated as "congestion" or "slightly congestion", the map information storage unit 24 stores the normal average vehicle speed for each normal link. May be calculated as the average vehicle speed, and in the case of a slight traffic jam, 20% of this vehicle speed may be calculated as the average vehicle speed.

Further, the road type correction section 68 performs correction by setting a coefficient D according to the type of road such as an expressway, a national road, and a general road. Generally, on arterial roads such as national roads, traffic flow is improved by controlling signals at successive intersections in association with each other.
Therefore, the travel time on such roads tends to be shorter. In addition, since the passenger drives while searching for the destination near the destination, the speed tends to be slightly lower. This is also corrected. FIG. 10 shows the correction coefficients of the correction unit 68.

Further, the road width correction unit 70 sets the coefficient E according to the road width and corrects the travel time. This takes into account that when the road width is wide, the traffic flow tends to be faster. FIG. 11 shows an example of the coefficient at this time.

Further, the lane regulation correcting section 72 sets a coefficient F corresponding to a link in which a part of the lane is restricted due to road construction or accident, and corrects the travel time. In lane regulation such as construction and accidents, the speed tends to be slow because the vehicle is placed in a situation that requires attention, such as a work vehicle crossing or passing by a worker walking. Correct to accommodate. The correction coefficient is set to, for example, 1.2.

[0095] and more than equivalent length, estimated travel time T'by each of the correction coefficient is,

(Equation 3) Is calculated as

In this case, the average speed is calculated based on the information on the degree of traffic congestion as described above. However, in the case of a link for which no information on the degree of traffic congestion is obtained, the average speed is calculated from the past data by time zone. The average vehicle speed information may be stored in the map information storage means 24 in advance, and the average vehicle speed V may be determined based on this information.

Next, calculation of the link travel time corresponding to the time-limited traffic regulation will be described. Such restrictions include, for example, road closures due to construction and accidents and winter road closures. FIG.
Shown in The map information storage unit 24 stores in advance the average vehicle speed and the link length for each time zone for each link, and based on this, the passage time of the link when there is no regulation is calculated by the passage time calculation unit 74. Further, the waiting time in front of the closed road link is calculated by the waiting time calculating unit 76 from the difference between the estimated time of arrival before the closed road link and the time of the scheduled closing of the closed road. The travel time of the link is calculated by the travel time calculation unit 78 as the sum of the calculated transit time and the waiting time.

As described above, by considering the time until the suspension of traffic, it is possible to cope with the case where it is faster to wait until the suspension of traffic is released and pass the link even if the traffic is currently closed.

Next, a case where a travel time of a link having no travel time information is estimated from a travel time of a neighboring link is described. The configuration of the device is shown in FIG.
The travel time estimating unit 80 obtains an average vehicle speed from the travel time and the link length of the links before and after the link to which no travel time is assigned, and estimates the travel time assuming that the link can run at this vehicle speed.

Alternatively, the average of the travel times of the left and right links in parallel may be taken. Since the link lengths of the parallel left and right links are almost equal to the link in many cases, even if the travel time is directly estimated without obtaining the average vehicle speed, the estimation can be performed without significantly lowering the accuracy.

Furthermore, the whole country was divided into 10km sections.
From the information on the average degree of congestion in the so-called secondary mesh, the travel time of a link in the secondary mesh to which no travel time is assigned may be estimated. That is, the average vehicle speed is obtained from the average congestion degree, and the travel time is estimated from the link length of the link. It is also preferable to calculate the average degree of congestion for a mesh that is further subdivided when it is large in a secondary mesh section.

Next, a description will be given of the calculation of the travel time when the link travel time information cannot be received only this time for some reason. The configuration of this device is shown in FIG. It is presumed that the travel time information received at the time of the previous reception and the travel time information that should have been received this time do not often have a significant difference. Therefore, in the present apparatus, the route search is performed by treating the information received last time as the travel time of this time. In particular, it is preferable that the beacon receiver 36 and the FM multiplex receiver 34 are configured so that the previous information is updated only for the obtained information, and the previous information remains for items for which no information is obtained.

Further, a storage unit for storing received information of a plurality of times in the past is provided with a beacon receiver 36 and an FM multiplex receiver 3.
4, it is also preferable to extrapolate the current travel time based on changes in the past multiple travel times. In this case, when the traffic congestion is getting worse, a travel time longer than the previous travel time is estimated from this tendency.

Next, a case where the link travel time is corrected according to the weather will be described. FIG. 15 shows the configuration.
The weather information detection unit 84 detects weather-related information from the received information, and performs correction according to the weather detected by the weather candidate correct unit 86. The weather information detection unit 84 preferably detects the weather by operating the vehicle by a passenger, in addition to detecting the weather based on external information. For example, when the wiper is made differential, it is rain, and when the fog lamp is turned on, it is fog. In addition, traction control (TR
The estimation may be performed based on the operation state of C).

FIG. 16 shows a control flow of the correction relating to the weather. Traffic information is acquired (S10
0), a route search is performed (S102), and an arrival time is predicted (S104). Then, when rainfall information is detected from the external information or the wiper switch (S106, S10)
8) A coefficient is set (S110). This coefficient is for increasing the travel time. Next, fog detection is performed.
Also in this case, judgment is made based on external information or fog lamps (S112, S114), and coefficient setting is performed (S11).
6).

The arrival time is corrected based on these coefficients, and the passenger is notified (S118). Then, the vehicle starts running (S120). Then, when the traction control detects a slip (S122), it is determined whether this value is a normal value or a value larger than this (S124). If it is more than normal, it is determined whether the slip is stationary (S126). If it is constantly large, it is determined that the tire is worn (S128), and a coefficient is set to delay the arrival time. (S13
0). If it is determined in step S126 that the slip is not constantly large, it is determined whether the slip after the accelerator is turned on is large (S132). In this case, it is determined that it depends on the road surface condition (S134), and the coefficient is set accordingly (S136). Step S13
0, the arrival time is corrected again by the coefficient set in S136, and the passenger is notified (S138).

Next, a description will be given of a case where a route that does not burden the driver and is easy to drive is selected. FIG. 17 shows the configuration of this device. In the driving environment evaluation unit 88, a cost and a coefficient according to ease of driving are set, and a route search is performed by the route search unit 90 based on these. The evaluation of ease of driving includes link length, road type,
Degree of congestion in the oncoming lane, presence or absence of traffic lights at intersections, degree of congestion in the oncoming lane when turning left or right, visibility distribution that is the distance seen by the driver, surrounding road environment such as whether the surroundings are residential or shopping, The ease of driving is determined based on the evaluation of whether there is a sidewalk, whether there is a pedestrian crossing, whether there is a pedestrian crossing, whether there is a crosswalk, the width of the road, the presence or absence of driving experience of the driver, and the like. In this way, the evaluation of the ease of driving makes it possible to search for a comfortable road with little burden on the driver.

The apparatus for searching for the optimum route at that time based on external information has been described above. However, as described above, the shortest route is also searched, both are displayed, and the passenger can select this. It is also preferable to be configured as follows.

[0109]

As described above, according to the present invention, a more accurate route search can be performed by correcting the received travel time based on various conditions. Further, by estimating the travel time for a link for which travel time information has not been obtained or cannot be obtained, a more precise route search can be performed.

According to the first aspect of the present invention, when a travel time such as traveling at a speed higher than a normally conceivable speed is received, this information is rejected, so that information containing noise or the like is received. , And more accurate travel time calculation can be performed.

According to the second and third aspects of the present invention, the reliability of the link travel time is determined by determining whether the content obtained from the received link travel time information and the information obtained from the traffic congestion information match each other. Secure. As a result, it is possible to calculate the travel time with higher accuracy.

According to the fourth aspect of the present invention, when a right turn or a left turn is performed at the end of the link, the received link travel time is corrected in consideration of the time required for the right or left turn, thereby obtaining the travel time. Accuracy can be improved. The time required for turning right and left is determined by the oncoming lane and intersection
By expressing it as a function of road traffic,
The right / left turn time can be calculated.

[0113]

[0114]

According to the fifth aspect of the present invention, while traveling on a toll road, the toll road is preferentially searched for, so that the driver once gets down to the general road and gets on the toll road again, and pays the toll twice. Can be prevented.

In the invention according to claim 6 , by allocating the received link travel time to more subdivided links, it is possible to perform a route search for a finer route.

According to the invention described in claim 7 , by subtracting the signal waiting time from the subdivided link travel time in claim 6, a more accurate small link travel time can be calculated.

According to the invention described in claims 8 to 14 , for a link for which no link travel time has been received, the travel time of this link is estimated. Claim 8 and
When the congestion degree is obtained as the external information as in 10, the average vehicle speed is calculated from the congestion degree, and the travel time is estimated. Also, as in claims 9 and 11, when the information of the congestion degree can not be obtained estimates the link travel time to determine the average vehicle speed on the basis of another average vehicle speed time for each link stored as a database. Claim 10
In ( 11) and ( 11) , for example, a route search is performed by evaluating information on dynamically changing traffic regulation such as an accident, so that it is possible to prevent a route that travels on a closed road in reverse from being searched. Furthermore, in claim 12 , the road type, in claim 13 , the road width, and in claim 14,
In, the link travel time is estimated with higher accuracy based on information such as lane regulation.

[0119] In the invention according to the fifteenth aspect , the restriction of the current link is restricted by calculating the waiting time based on the time at which the restriction is released for the currently restricted link. The route that passes after waiting for can be selected.

According to the inventions of claims 16 to 19 , for a link for which travel time information has not been obtained, the width of the search route is widened by estimating it from the surrounding link travel time and obtaining it. In the invention according to claim 17 , the travel time can be estimated from the link travel times before and after the link. In the invention described in claim 18 , the travel time can be estimated from the left and right links parallel to the link. Further, in the invention according to claim 19 , it is possible to estimate the link travel time in a predetermined area based on the average congestion degree in the area.

According to the twentieth and twenty-first aspects of the present invention, it is possible to estimate a link travel time for a link for which link travel time information was not obtained, based on previous or plural past information. . In the invention according to claim 20 , when travel time information is not obtained,
The previous travel time information is treated as this time. According to the twenty-first aspect , it is possible to extrapolate the information of a plurality of times in the past to estimate the travel time of the present time.

[0122]

According to the invention described in claim 22 , a road which is easy for the driver to drive can be searched, so that the burden on the driver can be reduced.

According to the twenty- third aspect of the present invention, the search for the shortest route is performed simultaneously with the invention described in any one of the above-mentioned aspects, and the two are compared and displayed, so that the passenger can be selected. The width can be expanded.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a part of the configuration of a preferred embodiment according to the present invention.

FIG. 2 is a block diagram showing a part of the configuration of a preferred embodiment according to the present invention.

FIG. 3 is a table showing an example of right / left turn costs.

FIG. 4 is a block diagram showing a part of the configuration of a preferred embodiment according to the present invention.

FIG. 5 is a block diagram showing a part of the configuration of a preferred embodiment according to the present invention.

FIG. 6 is a block diagram showing a part of the configuration of a preferred embodiment according to the present invention.

FIG. 7 is a block diagram showing a part of the configuration of a preferred embodiment according to the present invention.

FIG. 8 is a diagram illustrating the correspondence between a link to which travel time is sent and a divided small link.

FIG. 9 is a block diagram showing a part of the configuration of a preferred embodiment according to the present invention.

FIG. 10 is a table showing an example of a correction coefficient determined for each road type.

FIG. 11 is a table showing an example of a correction coefficient determined for each road width.

FIG. 12 is a block diagram showing a part of the configuration of a preferred embodiment according to the present invention.

FIG. 13 is a block diagram showing a part of the configuration of a preferred embodiment according to the present invention.

FIG. 14 is a block diagram showing a part of the configuration of a preferred embodiment according to the present invention.

FIG. 15 is a block diagram showing a part of the configuration of a preferred embodiment according to the present invention.

FIG. 16 is a flowchart showing a control flow of the embodiment shown in FIG.

FIG. 17 is a block diagram showing a part of the configuration of a preferred embodiment according to the present invention.

[Explanation of symbols]

 22 control unit 34 FM multiplex receiver 36 beacon receiver 42 speed calculation unit 44 rejection instructing unit 46 congestion degree detection unit 48 required time calculation unit 50 right / left turn correction unit 52 right / left turn time change unit 54 selection frequency calculation unit 56 selection frequency correction unit 58 Toll road priority correction unit 60 Small link setting unit 62 Small link travel time calculation unit 64 Link equivalent length calculation unit 66 Average vehicle speed calculation unit 68 Road type correction unit 70 Road width correction unit 72 Lane regulation correction unit 74 Passage time calculation unit 76 Waiting time calculating section 78 Travel time calculating section 80 Travel time estimating section 82 Travel time calculating section 84 Weather information detecting section 86 Sky candidate correct section 88 Driving environment evaluating section 90 Route searching section

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tohru Ito 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Akihiko Nojima 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation ( 72) Inventor Masaharu Hirota 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (56) References JP-A-62-60100 (JP, A) JP-A-2-244399 (JP, A) JP-A Heisei 5-118866 (JP, A) JP-A-1-141313 (JP, A) JP-A-1-130299 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G08G 1/09 -1/0969 G01C 21/00-21/36 G09B 29/10

Claims (23)

(57) [Claims] 1. A route guidance device for a vehicle that searches for an optimal route to a destination based on a link travel time included in information sent from outside the vehicle, notifies the occupant of the route, and performs route guidance. A speed calculating means for calculating a required speed of the link from the link travel time and a length of the link, and when the required speed is equal to or more than a predetermined value, the link travel time is not adopted in the route search. A route guidance device for a vehicle, comprising an adoption instruction unit. 2. A vehicle route guide that searches for an optimum route to a destination based on link travel time included in external information sent from outside the vehicle, notifies the occupant of the route, and performs route guidance. A speed calculating means for calculating a required speed of the link from the link travel time and a length of the link; and a congestion degree for detecting a congestion degree included in the external information and representing a degree of congestion as an average vehicle speed. When the detection means and the required speed and the congestion degree are compared and they do not match,
A vehicle route guidance device comprising rejection instruction means that does not employ the link travel time. 3. A route guidance for a vehicle that searches for an optimal route to a destination based on link travel time included in external information sent from outside the vehicle, notifies the occupant of the route, and performs route guidance. In the apparatus, a traffic congestion degree detecting means for detecting a traffic congestion degree included in the external information and representing the degree of traffic congestion as an average vehicle speed, and a required time for calculating a required transit time of the link from the traffic congestion degree and the length of the link A vehicle route comprising calculating means, and comparing the required time with the travel time of the link, and if they do not match, a rejection instructing means that does not use the link travel time when searching for a route. Guidance device. 4. A route guidance for a vehicle that searches for an optimal route to a destination based on link travel time included in external information sent from outside the vehicle, notifies the occupant of the route, and performs route guidance. In the device, a right / left turn correction means for correcting the link travel time based on the information on the right / left turn of the intersection, and a right for changing the time required for the right / left turn based on at least one of the traffic condition of the oncoming lane and the traffic condition of the intersection road. A vehicle route guidance device, comprising: left turn time changing means; 5. A vehicle route guide that searches for an optimal route to a destination based on link travel time included in external information sent from outside the vehicle, notifies the occupant of the route, and performs route guidance. in the device, in toll road Michihashi line, vehicle route guidance device characterized by having a toll road priority correction means for correcting to the link travel time to give priority to the toll road. 6. A route guidance for a vehicle that searches for an optimal route to a destination based on link travel time included in external information sent from outside the vehicle, notifies the occupant of the route, and performs route guidance. A small link setting means for further dividing the link to which the link travel time information is added into a plurality of small links; and a small link for calculating the small link travel time by proportionally distributing the link travel time according to the distance of the small link. A vehicle route guidance device having link travel time calculation means. 7. A vehicle route guide that searches for an optimal route to a destination based on link travel time included in external information sent from outside the vehicle, notifies the occupant of the route, and performs route guidance. A small link setting means for further dividing the link to which the link travel time information is given into a plurality of small links; and distributing the link travel time in proportion to the distance of the small link to reduce a signal waiting time to reduce the small link travel time. A route guidance device for a vehicle, comprising a small link travel time calculation means for calculating time. 8. A vehicle route guidance that searches for an optimal route to a destination based on link travel time included in external information sent from outside the vehicle, notifies the occupant of the route, and performs route guidance. In the apparatus, link equivalent length calculating means for calculating a link equivalent length from the right and left turn equivalent length representing the time required for right and left turn by the road length and the actual link length, and an average vehicle speed of the link from the congestion degree information included in the external information And a link travel time calculating means for calculating a link travel time from the link equivalent length and the average vehicle speed for a link for which a link travel time was not obtained from external information. Vehicle route guidance device characterized by the above-mentioned. 9. A vehicle route guide that searches for an optimal route to a destination based on link travel time included in external information sent from outside the vehicle, notifies the occupant of the route, and performs route guidance. In the apparatus, link equivalent length calculating means for calculating a link equivalent length from the right and left turn equivalent lengths representing the time required for right and left turns by the road length and the actual link length, and an average vehicle speed for each time zone for each link are stored in advance. Storage means, and link travel time calculation means for calculating a link travel time from the link equivalent length and the average vehicle speed of the storage means for a link for which the link travel time was not obtained from external information. Vehicle route guidance device. 10. A vehicle route guide that searches for an optimal route to a destination based on link travel time included in external information sent from outside the vehicle, notifies the occupant of the route, and performs route guidance. In the device, the equivalent length of right and left turns, which represents the time required for turning right and left, by the road length, the equivalent length of traffic, which represents the time required for traffic regulation by the road length, and the equivalent of a link that calculates the equivalent link length from the actual link length Length calculation means; average vehicle speed calculation means for calculating an average vehicle speed of the link from the congestion degree information included in the external information; link-equivalent length and the average vehicle speed for a link whose link travel time was not obtained from the external information And a link travel time calculating means for calculating a link travel time from the following. 11. A vehicle route guide that searches for an optimal route to a destination based on link travel time included in external information sent from outside the vehicle, notifies the occupant of the route, and performs route guidance. In the device, the equivalent length of right and left turns, which represents the time required for turning right and left, by the road length, the equivalent length of traffic, which represents the time required for traffic regulation by the road length, and the equivalent of a link that calculates the equivalent link length from the actual link length Length calculation means, storage means in which an average vehicle speed for each time zone for each link is stored in advance, and for links for which link travel time was not obtained from external information, the link equivalent length and the average vehicle speed of the storage means. A vehicle route guidance device, comprising: link travel time calculation means for calculating link travel time. 12. A vehicle navigation system according to claim 8 11, the vehicle path and having a road type correction means for correcting the link travel time based on road type of the link Guidance device. 13. A vehicle navigation system according to any one of claims 8 12, the vehicle path and having a road width correction means for correcting the link travel time based on road width of the link Guidance device. 14. A vehicle navigation system according to any one of claims 8 to 13, for a vehicle, characterized in that it comprises a lane restrictions correcting means for correcting the link travel time based on the lane regulation information for links Route guidance device. 15. A vehicle route guide that searches for an optimum route to a destination based on link travel time included in external information sent from outside the vehicle, notifies the occupant of the route, and performs route guidance. In the apparatus, a storage means in which an average vehicle speed for each time zone for each link is stored in advance, and for a link having temporary traffic restriction information, a passage time of the link is calculated based on the average vehicle speed for each time zone and the link length. Transit time calculating means, a waiting time calculating means for calculating a waiting time until the suspension of traffic regulation is released, and a travel time calculating means for calculating a traveling time of the link from the passing time and the waiting time. A route guidance device for a vehicle, comprising: 16. A vehicle route guidance that searches for an optimal route to a destination based on link travel time included in external information sent from outside the vehicle, notifies the occupant of the route, and performs route guidance. In the apparatus, for a link for which the link travel time information cannot be obtained,
A route guidance device for a vehicle, comprising travel time estimation means for estimating the travel time of a peripheral link from the travel time of a peripheral link. 17. The vehicle route guidance device according to claim 16 , wherein the travel time estimating means estimates travel time based on travel times of links before and after the link. Route guidance device. 18. The vehicle route guidance device according to claim 16 , wherein said travel time estimating means estimates travel time based on travel times of left and right links parallel to said link. Route guidance device for vehicles. 19. The vehicle route guidance device according to claim 16 , wherein the travel time estimating means is based on an average degree of congestion in a secondary mesh including the link or a mesh obtained by further subdividing the secondary mesh. A vehicle route guidance device for estimating a link travel time. 20. A vehicle route guide that searches for an optimal route to a destination based on link travel time included in external information sent from outside the vehicle, notifies the occupant of the route, and performs route guidance. A route guidance device for a vehicle, comprising: a travel time calculation unit that calculates a link travel time based on information at a previous reception for a link for which the link travel time information was not obtained. 21. A vehicle route guide that searches for an optimal route to a destination based on link travel time included in external information sent from outside the vehicle, notifies the occupant of the route, and performs route guidance. A vehicle route guidance device having a travel time estimating means for estimating a link travel time for a link for which the link travel time information was not obtained based on information of a plurality of receptions in the past. 22. A vehicular route guidance device that searches for an optimal route to a destination based on external information sent from outside the vehicle, notifies the occupant of the route, and performs route guidance. Driving environment evaluation means for evaluating easiness of driving based on surrounding conditions, and route search means for calculating a route determined to be most easy to drive based on the evaluation of the driving environment as an optimal route. Vehicle route guidance device. 23. The vehicle route guidance device according to any one of claims, wherein: a shortest route search unit that searches for a shortest route; and a comparison display unit that compares and displays the shortest route and the optimal route. A route guidance device for a vehicle, comprising: