JPH08201096A - Route guidance system - Google Patents

Abstract

PURPOSE: To obtain a route guidance system in which unnecessary guidance is prevented at an intersection and a route guidance fitted to the traveling feeling of a driver can be realized. CONSTITUTION: When a plurality of branch paths are present at an intersection and a decision is made that a recommended route is not the straight entering path (S3), the guidance of recommended route is not performed so long as the recommended route is present within a predetermined angle from the straight advancing direction of entering path (S8), the recommended path is a road of the same class as the entering path and other branch paths within the predetermined angle do not include a road more important than the recommended path (S10, S11).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a route guide device mounted on a vehicle and used, and in particular, guides a recommended route for a vehicle to travel from among a plurality of branch roads at an intersection having a plurality of branch roads. The present invention relates to a route guidance device.

[0002]

2. Description of the Related Art Conventionally, a navigation device, which is a route guidance device for guiding a driver (user) to a recommended route to a destination, has been used in order to support traveling by a vehicle on an unguided land. In the above navigation device, the control unit including the central processing unit detects the current position of the vehicle based on the traveling distance and the traveling direction of the vehicle detected by the distance sensor and the direction sensor, respectively, and the detected current position of the vehicle. CR along with the road map around it
Display on a display device composed of T or liquid crystal display element,
It guides the user to the recommended route to the destination.

Further, in the conventional navigation device, the driver visually recognizes a small vehicle mark or a detailed recommended route display on the screen of the display device while driving, especially when the driver approaches the intersection when driving in the city. Since it is not preferable for traffic safety, when the intersection that the vehicle should pass is approaching, the driver is informed by voice of the direction to proceed, and a large arrow indicating the traveling direction is displayed to correspond to the intersection shape. By doing so, the driver was informed of the recommended route. In this case, the driver can obtain the information of the recommended route while keeping a close eye on the front or by simply glancing at the screen, and it is possible to improve the traffic safety.

[0004]

However, in the above-mentioned conventional navigation device, unnecessary recommended route guidance is provided at the intersection, which does not match the driver's sense of running, and the driver is confused and confused. There was a problem. FIG. 4 is a diagram for explaining the above problems of the conventional navigation device. Referring to FIG. 4, when the driver travels on approach road I1 and approaches an intersection having two fork roads O1 and O2, exit road O1 is selected as a recommended route as indicated by an arrow. In this case, in the conventional navigation device, when the voice is notified, the driver is informed of the recommended route with a voice such as "The next branch is to the right." In this case, the approach road I1 and the exit road O1 are one road, and since the exit road O1 is a main road having a wider road width than the exit road O2, the driver feels that the driver should drive along the road. Therefore, if the voice informs that "the next branch is to the right", there is an exit to the right of the exit O1 and it may be necessary to make a right turn to the exit. To have
There was a problem that the driver was confused. As described above, the conventional navigation device has a problem that the driver confuses in which direction the driver should proceed because unnecessary guidance is provided in a state different from the driver's sense of running.

The present invention is intended to solve the above problems, and it is possible to prevent unnecessary guidance from being provided at intersections and to provide route guidance suitable for the driver's sense of running. An object is to provide a route guidance device.

[0006]

A route guide device according to claim 1 is a route guide device for guiding a recommended route for a vehicle to travel from among a plurality of branch roads at an intersection having a plurality of branch roads. , Comparing the road attribute information of the recommended route and the road attribute information of the approach route with the angle detection means that detects that the recommended route is within a predetermined angle from the straight direction as seen from the approach route where the vehicle has entered the intersection If there is a recommended route and an exit route that is a branch route other than the approach route within a predetermined angle, a comparison means that determines whether the recommended route is a major road than the exit route, and guides the recommended route. The guide means detects that the recommended route is within a predetermined angle by the angle detecting means, and the comparing means determines that the road attribute information of the recommended route and the road attribute information of the approach road are the same. It is determined to be, furthermore, when the recommended route the judgment means judges that the main road from the exit road, not performed the guidance of the recommended route.

The route guide device according to claim 2 is the same as that of claim 1.
In addition to the configuration of the route guidance device described, the road attribute information includes at least information about road type and information about road width, and the comparison means compares the information about road type and the information about road width.

A route guidance device according to a third aspect of the present invention is the first aspect.
Alternatively, in addition to the configuration of the route guidance device described in 2, the determining unit compares at least the information regarding the road type and the information regarding the width of the road, and determines that the recommended route is a main road rather than the exit route.

[0009]

In the route guidance device according to the first aspect, the angle detecting means determines that the recommended route is at a predetermined angle, and the comparing means determines that the road attribute information of the recommended route and the road attribute information of the approach road. If it is determined that they are the same, and if the determining means determines that the recommended route is a main road than the exit route, the guiding means does not guide the recommended route. Therefore, for example, if the approach route and the recommended route are roads that are roads and the recommended route is a main road, the driver will not be guided and the driver will not drive the road. Therefore, it is possible to continue driving smoothly without being confused by unnecessary guidance.

In the route guidance device according to claim 2,
In addition to the operation of the route guidance device according to claim 1, it is possible to determine whether or not the recommended route and the approach route are the same by using the information about the road type and the information about the width of the road. It is possible to determine the identity of the recommended route and the approach route using a small amount of attribute information, and the determination process can be performed simply and quickly, and the amount of information to be stored can be reduced. .

In the route guiding device according to claim 3,
In addition to the operation of the route guidance device according to claim 1 or 2, the determination means can determine that the recommended route is a main road rather than the exit route by using the information about the road type and the information about the width of the road. Therefore, it is possible to make a determination using a small amount of information among a plurality of road attribute information, the determination process can be performed simply and at high speed, and the amount of information to be stored can be reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A car navigation system which is a route guidance system according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a car navigation device that is an embodiment of the present invention.

Referring to FIG. 1, the car navigation system includes a distance sensor 1, an azimuth sensor 2, a geomagnetic sensor 3, a position detection device 4, a display device 5, a controller 6, a road map memory 7, a memory drive 8, and beacon reception. Machine 9, GP
An S (Global Positioning System) receiver 10, an input device 11, and an audio output device 12 are included. The controller 6 also includes a voice data memory 13.

The navigation system of this embodiment is mounted on a vehicle and is used. A distance sensor 1 for detecting the traveling distance of the vehicle, a direction sensor 2 for detecting the traveling direction of the vehicle, and a geomagnetic sensor for detecting the earth's magnetic field. The current position of the vehicle is detected by the position detection device 4 based on each output of 3 and the detected current position is displayed on the display device 5 composed of a CRT, a liquid crystal display element and the like, together with a road map around it. That is, when the current position of the vehicle detected by the position detection device 4 is given to the controller 6, the controller 6 causes the road map memory 7 configured by a CD-ROM to pass a predetermined range near the current position via the memory drive 8. The road map data is read, and the current position is superimposed on the read road map and displayed on the display device 5.

The detection of the current position by the position detecting device 4 is
Basically, so-called self-contained navigation based on the outputs of the distance sensor 1 and the direction sensor 2 is used. That is, the position detection device 4 integrates the output of the distance sensor 1 over a predetermined time and also integrates the output of the azimuth sensor 2 during the predetermined time. As a result, the traveling distance of the vehicle in the predetermined time period can be obtained from the integrated value of the distance sensor 1,
The traveling direction can be obtained from the integrated value of the direction sensor 2. Therefore, for example, if the correct position of the vehicle is input using the input device 11 before starting the vehicle, the transition of the vehicle position thereafter can be detected.

The position detecting device 4 may detect the current position by using a so-called map mapping method using the position detecting road map data stored in the road map memory 7. In this case, the current position is corrected to a position on the road in the vicinity thereof by utilizing the fact that the position of the vehicle is limited on the road in principle. As a result, it is possible to prevent the error of the current position detected based on the outputs of the distance sensor 1 and the azimuth sensor 2 from being accumulated, and improve the accuracy of position detection.

A beacon receiver 9 is connected to the position detecting device 4. The beacon receiver 9 is for receiving data such as position information and road information (intersection name, destination guidance, traffic jam information, accident information) radiated from a beacon antenna installed on the roadside of the road. The road information received by the beacon receiver 9 is given to the controller 6 and finally displayed on the display device 5.

Further, a GPS receiver 10 is connected to the position detecting device 4. The GPS receiver 10 receives radio waves transmitted from GPS satellites that are orbiting the earth. The position detecting device 4 directly detects the current position of the vehicle based on the transmission delay time of the received radio waves.

In the position detecting device 4, based on the current position obtained by the self-contained navigation, the current position obtained based on the position information received by the beacon receiver 9 or the radio wave received by the GPS receiver 10. One of the obtained current positions is selectively adopted according to a predetermined standard to detect the current position of the vehicle.

The road map memory 7 stores display road map data, position detection road map data, route calculation road map data, and the like. As each of the above data, intersection traffic code, administrator code, road classification code, main / sub road classification code, administrative classification code, link classification code, link traffic allowed / vehicle prohibited code, abnormal weather traffic regulation section classification code, A road width distinction code, a lane number code, a traffic regulation type code, etc. are included. In this embodiment, at least a road type code and a road width classification code are stored among the above codes. Highway national roads, urban highways (including designated city highways), general national roads, major local roads (prefectural roads), major local roads (designated city roads), general prefectural roads, designated cities No. 1 to No. 9, 0 are assigned to each of the general roads, other roads, and unexamined roads. Also,
As road width division code, width 13.0m or more, width 5.5 or more to less than 13.0m, width 3.0m or more to
Codes of 1 to 4, 0 are assigned corresponding to less than 5.5 m, width less than 3.0 m, and unexamined. Therefore, the road type code and the road width classification code from the road map memory 7 are transferred to the controller 6 via the memory drive 8.
Is output to the controller 6, and the controller 6 uses the read codes to execute a guidance process described later.

An input device 11 for selecting various functions and a voice output device 12 for outputting a voice at the time of route guidance are connected to the controller 6, respectively. The controller 6 further has a ROM in which voice data to be output at the time of route guidance is stored as a voice data table.
Audio data memory 1 composed of (Read Only Memory)
3 is provided. The voice data memory 13 stores various voice data such as "the next branch is to the right", and the controller 6 reads out predetermined voice data from the voice data memory 13 as necessary to output the voice output device 12
Is used to guide the driver to a recommended route with a predetermined voice.

Inside the controller 6, there is provided a route guidance processing section which functions as the center of operation of the controller 6. The current position data of the vehicle is given from the position detecting device 4 to the route guidance processing unit, and when the current position data is given, the route guidance processing unit gives the road map data for display around the given current position. The road map memory 7 is read from the road map memory 7 via the memory drive 8 into the road map memory control unit inside the controller 6. The read display road map data and current position data are supplied to the display device 5 after being supplied to the display control unit inside the controller 6 and processed into display data. As a result, the display device 5 displays the current position of the vehicle in an overlapping manner on the road map.

An input device 11 is connected to the route guidance processing unit via an input control unit inside the controller 6.
When the route calculation request signal and the destination data are given from the input device 11 through the input control unit, the route guidance processing unit causes the road map memory control unit to read the road calculation road map data from the road map memory 7, The read route calculation road map data, destination data, and current position data are given to the route calculation processing unit in the controller 6. In the route calculation processing unit, an optimum route to the destination is calculated as a recommended route by the Dijkstra method, for example, based on the given route calculation road map data, destination data and current position data.

The Dijkstra method uses a node or a link closest to a destination (which may be the current position) as a starting point,
Assuming a tree of links from the start point to the end point with the node or link closest to the current position (which may be the destination) as the end point, calculate all link costs (link travel time and travel distance) that make up the tree This is a method of sequentially adding and selecting only the route having the lowest link cost to reach the end point.

When the recommended route is calculated, the route guidance processing unit gives the calculated recommended route to the display control unit and also creates and stores a guide table representing the calculated recommended route.

In the display control unit, the given recommended route is processed into display data, and the processed display data is given to the display device 5. As a result, on the display device 5, the recommended route is displayed by, for example, a dotted line. Further, the voice control unit in the controller 6 reads out the voice content to be output in the route guidance processing from the voice data memory 13,
A predetermined voice content is given to the voice output device 12 based on the read data.

Next, the route guidance processing of the navigation device shown in FIG. 2 will be described. FIG. 2 is a flowchart for explaining the route guidance processing of the navigation device shown in FIG.

Referring to FIG. 2, first, in step S1, when the vehicle is located near the intersection, it is determined whether or not there are a plurality of branch roads at the intersection in the traveling direction. If there are no multiple branch paths, there is no need to guide the route, so the process ends. If there are multiple branch paths,
Control goes to step S2.

Next, in step S2, step S
It is determined whether the recommended route among the plurality of branch roads detected in 1 is a highway entrance / exit or a highway main road branch. In the case of the entrance or exit of the expressway or the branch of the expressway main line, the process proceeds to step S7, and in order to guide the driver to the recommended route, route guidance processing is performed, and the driver is guided to the recommended route by voice.

On the other hand, if it is not the entrance of the expressway or the branch of the expressway main line, the process proceeds to step S3, and it is judged whether or not the recommended route is in the straight traveling direction as viewed from the approaching route. If the recommended route is in the straight traveling direction, the process proceeds to step S4, and if it is not in the straight traveling direction, the process proceeds to step S8.

If the recommended route is in the straight direction, step S4
At, it is determined whether or not there is a branch road other than the recommended road within a predetermined angle centered on the straight direction as seen from the approach road. If there is another branch road, the process proceeds to step S5, and if there is no other branch road, there is no need to guide the recommended route, and the process ends.

If there is another branch road, it is judged in step S5 whether or not the other branch road detected in step S4 is the same road as the approach road, that is, the road of the same grade. Specifically, as the road attribute information of the branch road and the approach road, the road type code that is the information about the road type and the road width division code that is the information about the width of the road are compared, and the branch road and the approach road are equal. It is determined whether or not it is a road. When the branch road and the approach road are roads of the same grade, that is, the approach road and the branch road are roads that are not roads, and the approach road and the recommended route are not roads, the recommended route is guided to step S6. On the other hand, if the branch road and the approach road are not equal roads, it is not necessary to guide the recommended route, and the process ends.

If it is determined that the branch road and the approach road are equal, it is determined in step S6 which of the recommended route and the branch road is the main road. In particular,
Similar to step S5, the road type code and the road width classification code are compared, and the road type code of the recommended route is a road type code lower than the road type code of the branch road,
When the road width classification code of the recommended route is narrower than the road width classification code of the branch road, it is determined that the branch road is the main road than the use route, and the procedure proceeds to step S7 to guide the recommended route, and the recommendation is made. Route guidance is provided.

On the other hand, when the road type code of the recommended route is a road type higher than the road type code of the branch road, and the road width classification code of the recommended route indicates a road width wider than the road width code of the branch road, that is, recommended If the route is a road that is more important than the branch road, it is not necessary to guide the recommended route, and the process ends.

When it is determined in step S3 that the recommended route is not in the straight traveling direction, it is determined in step S8 whether or not the recommended route exists within a predetermined angle centered on the straight traveling direction when viewed from the approach road. For example, it is determined whether or not the predetermined angle is within a range of 60 ° in width centering on the straight traveling direction viewed from the approach road. If the recommended route is within the predetermined angle, the process proceeds to step S9. If the recommended route is not within the predetermined angle, the recommended route is in a direction that is largely curved from the approach road, and guidance of the recommended route is required. Therefore, the process proceeds to step S7. However, the recommended route is guided.

If the recommended route is within the predetermined angle, it is determined in step S9 whether or not the recommended route has the same grade as the approach route. Specifically, at least the road type code and the road width classification code of the recommended route and the approach road are compared, and it is determined whether or not the road type and the road width are the same. If the recommended route is not the same as the approach route, that is, if the recommended route is not the approach route, the process proceeds to step S7 to guide the recommended route.

On the other hand, if the recommended route is a road having the same grade as the approach road, it is determined that the recommended route is a road that is close to the approach road, and the process proceeds to step S10. Here, only the road type code and the road width classification code are used as the road attribute information to judge whether the roads are of the same rank or not.
It may be determined using the link type code and the route number data of the road. In this case, it is possible to more accurately determine whether or not the roads have the same grade. As the link type code, main line (non-separated upper and lower lines) link, main line (separated upper and lower lines) link, connecting road (crossover line between main lines) link, intersection link, connecting road (ramp) link, same line as main line Side road links, service area side line links, bicycle path links, etc. are used, and codes of 1 to 8, 0 are assigned to each, and roads are classified as equal by comparing these codes. Is determined.

As the route number of the road, for example, the route number such as 1 in the case of National Route 1 and 2 in the case of National Route 2 is stored in advance in the road map memory 7 as the above-mentioned road attribute information. By comparing these data, it is judged whether the roads are of the same grade or not. In addition,
The above-mentioned link is a vector connecting nodes that represent coordinate positions for identifying road intersections and the like. Further, the above-mentioned node is a coordinate position for identifying a road intersection or a bend.

If it is determined that the recommended route and the approach route are of the same grade, in step S10, it is determined whether or not there is another branch route other than the recommended route within a predetermined angle from the straight direction as viewed from the approach route. Is determined. Here, the predetermined angle is, for example, 60 ° as in step S8 above.
Range is used. If there is no other branch road within the predetermined angle, the driver can determine that the recommended route, which is the approach road and the road, should proceed as it is, and the process is terminated without guiding the recommended route.

On the other hand, if there is another branch road within the predetermined angle, it is determined in step S11 whether the recommended route is a main road than the branch road. To determine whether or not the recommended route is a road that is more important than the branch road, at least the road type code and the road width classification code are used as the road attribute information, as in step S9. Codes are compared. If the road type code of the recommended route has a higher road type than the road type code of the branch road and the road width classification code of the recommended route indicates a road width wider than the road width code of the branch road, the recommended route Is judged to be the main road than the branch road.

In this case, the recommended route is a road that is a road close to the approach route, and the other branch roads other than the recommended route are not the main roads as compared with the recommended route. Therefore, the direction of the recommended route is the approach road. Even if the road deviates from the straight ahead direction, the driver can determine that the vehicle should travel along the road, and the process is terminated without guiding the recommended route.

On the other hand, when it is determined that the recommended route is not the main road than the branch road, the process proceeds to step S7 to guide the recommended route. In this case, the recommended route is a road of the same grade as the approach route, but because the other branch roads other than the recommended route are the main roads, the driver is asked whether to drive the vehicle in the direction of the branch road. As I am lost, guidance of recommended route is given.

Next, the route guidance process according to the above flow chart will be described using a specific example. FIG. 3 shows FIG.
FIG. 8 is a diagram for specifically explaining the route guidance process shown in FIG. A case will be described with reference to FIG. 3 in which the vehicle of the driver travels on the approach road I1 and approaches the intersection at which the branch roads O1 and O2 are present.

First, when the branch road O1 is selected as the recommended route, it is determined in step S1 that there are two branch roads O1 and O2, and thus it is determined that there is a plurality of branch roads, and the process proceeds to step S2. Next, since the recommended route O1 is not a highway entrance or a highway main line branch, step S3
Move to. Next, in step S3, since the recommended route is not the straight direction of the approach road I1, the process proceeds to step S8.

Next, in step S8, since the recommended route is within the predetermined angle α, the process proceeds to step S9. Next, in step S9, it is determined that the recommended route and the approach road have the same grade, that is, the recommended route is the road that is the approach road, and the process proceeds to step S10. Next, since there is another branch road O2 within the predetermined angle α, the process proceeds to step S11. Next, in step S11, since the width of the branch road is narrower than the width of the recommended route,
It is determined that the recommended route is the main road from the branch road, the recommended route is not guided, and the process ends.

Therefore, in the conventional navigation device described with reference to FIG. 4, since the recommended route is guided in the above case, the driver may be confused as to which branch route should be selected. The example navigation device does not guide the recommended route, so the driver should select the recommended route and drive the vehicle even if the recommended route is not in the straight direction of the approach road. Therefore, it is possible to provide route guidance suitable for the driver's sense of running.

When the branch path O2 is selected as the recommended path, first, it is determined in step S1 that there are a plurality of branch paths, and the process proceeds to step S2. Next, it is determined that the recommended route O2 is not the entrance of the expressway or the branch of the expressway main line, and the process proceeds to step S3. next,
In step S3, the recommended route O2 is in the straight ahead direction of the approach road I1, so the process proceeds to step S4. Next, in step S4, since the branch road O1 which is another branch road exists within the predetermined angle α, the process proceeds to step S5. Next, it is determined that the branch road O1 and the approach road I1 are of the same grade, and the process proceeds to step S6. Next, it is determined that the recommended route O2 is not the main road than the branch road O1, and the step S
7, the voice guides the recommended route such as "go straight at the next branch". in this case,
As the driver's sense of running, the driver tries to drive in the direction of the branch road O1 which is a road that is the same as the approach road I1. However, since the recommended route is guided, the driver easily travels in the direction of the recommended route O2. can do.

As described above, in the navigation device of this embodiment, the recommended route is a road that bends from the approach road, and even if there is another branch road in the straight direction of the approach road, the recommended route is the approach road. If the road is a road, no guidance will be given.On the other hand, even if the recommended route is in the straight direction of the approach road, there are other branch roads along the approach road, and other branch roads are recommended routes. If it is a more main road, the recommended route is guided. Therefore, in the navigation device of the present embodiment, unnecessary guidance can be prevented from being provided at the intersection, and route guidance suitable for the driver's sense of running can be provided.

In the above embodiment, the voice is used as the method of guiding the recommended route, but the recommended route may be guided by displaying a predetermined screen on the display device 5. For example, when the recommended route O1 is selected in the example shown in FIG. 3, if only the approach route I1 and the recommended route O1 are displayed on the display device 5 and only one road is displayed, the route to the driver is displayed. No guidance will be given, while branch O
If 2 is selected as the recommended route, the recommended route O
2. Display other branch roads O1 and approach roads I1 and display an arrow or the like in the direction of the recommended route O2 to guide the recommended route so that the vehicle travels in the direction of the recommended route O2 instead of following the road. Good.

[0050]

According to the route guidance device of the present invention, it is determined that the recommended route is within a predetermined angle and the road attribute of the recommended route is the same as the road attribute of the approach road.
Furthermore, when it is determined that the recommended route is a main road than other branch roads, that is, the recommended route is the approach road even if there are multiple branch roads, and the recommended route is the main road. In some cases, the guidance of the recommended route is not performed, so that the driver can drive the vehicle according to the feeling of traveling, that is, the feeling that the driver should drive along a curved road. Therefore, it is possible to prevent unnecessary guidance from being provided at the intersection, and to provide route guidance suitable for the driver's sense of traveling.

In the route guidance device according to claim 2,
In addition to the effect of the route guidance device according to claim 1, since the recommended route and the approach route can be compared with each other by using the road attribute information having a small amount of information, the comparison process can be performed at high speed and easily and is stored. It is possible to reduce the amount of road attribute information that should be used.

In the route guidance device according to claim 3,
In addition to the effect of the route guidance device according to claim 1 or 2, it is possible to determine whether or not the recommended route is a main road than the exit route by the road attribute information having a small amount of information.
The determination process can be performed quickly and simply, and the amount of road attribute information to be stored can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a configuration of a navigation device according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining route guidance processing of the navigation device shown in FIG.

FIG. 3 is a diagram for specifically explaining the route guidance process shown in FIG.

FIG. 4 is a diagram for explaining a problem of a conventional navigation device.

[Explanation of symbols]

 1 Distance Sensor 2 Direction Sensor 3 Geomagnetic Sensor 4 Position Detection Device 5 Display Device 6 Controller 7 Road Map Memory 8 Memory Drive 9 Beacon Receiver 10 GPS Receiver 11 Input Device 12 Voice Output Device 13 Voice Data Memory

Claims (3)

[Claims] 1. A route guidance device which guides a recommended route for a vehicle to travel from among the plurality of branch roads at an intersection having a plurality of branch roads, wherein the recommended route allows the vehicle to enter the intersection. The angle detection means for detecting that it is within a predetermined angle from the straight direction as seen from the approach road, the comparison means for comparing the road attribute information of the recommended route and the road attribute information of the approach road, the predetermined angle When there is an exit route that is a branch road other than the recommended route and the approach route, a determination unit that determines that the recommended route is a road that is more main than the exit route, and a guide unit that guides the recommended route The guide means detects that the recommended route is within the predetermined angle by the angle detection means, and the road attribute information of the recommended route by the comparison means and the A road attribute information of entrance road is determined to be the same, and further,
A route guidance device that does not guide the recommended route when the determining unit determines that the recommended route is a road that is more main than the backward route. 2. The route according to claim 1, wherein the road attribute information includes at least information about a road type and information about a road width, and the comparison unit compares the information about the road type and the information about a road width. Guidance device. 3. The route according to claim 1, wherein the determination unit determines that the recommended route is a road that is more main than the backward route by comparing at least information regarding road types and information regarding road width. Guidance device.