JP6530331B2 - Map data generation apparatus, map data generation method and map data generation program - Google Patents

Description

  The present invention relates to a map data generation device, a map data generation method, and a map data generation program.

  Conventionally, a map data format has been known in which the geometric shape of a road is represented by a parametric curve (for example, Patent Document 1).

Patent No. 5591444 gazette

  The prior art has a problem that the amount of data can not be sufficiently reduced for roads having a linear shape.

According to the first aspect of the present invention, the map data generation device classifies the road whose road shape is represented by the first shape data representing the road shape by a plurality of points into a straight section and a curved section. Section, a point sequence thinning part that changes the road shape representation of the straight section to a first representation, and a road shape of the curved section is a second representation that is different from the first representation And an output unit for outputting, as second shape data, road shape data according to the expression changed by the point sequence thinning-out unit and the curving unit, and the first expression or the second expression A lane for changing the road shape of a road including a plurality of lanes expressed in expression to a information including the road shape of at least one of the plurality of lanes and the number of lanes of the plurality of lanes and the road width table The vehicle control apparatus further comprises a change unit, wherein the lane expression change unit deletes road shape data of the road for at least one lane of road shapes of the road including the plurality of lanes, and the output unit changes the lane expression The data of the road shape by the expression changed by the unit is output as the second shape data.
According to the second aspect of the present invention, the map data generation method is a shape determination that classifies a road whose road shape is represented by first shape data representing the road shape by a plurality of points into a straight section and a curved section. Changing the representation of the road shape of the straight section to the first representation; changing the representation of the road shape of the curved section to the second representation different from the first representation A step of curving, a step of outputting road shape data based on the representation modified by the point train thinning step and the step of curving, as the second shape data, and representation by the first representation or the second representation Changing the road shape of a road including the plurality of lanes to a representation including the road shape of at least one of the plurality of lanes and the information on the number of lanes and the width of the plurality of lanes The lane representation changing step deletes data of the road shape of the road for at least one lane of the road shapes of the road including the plurality of lanes, and the lane portion includes the lane representation changing step The data of the road shape by the expression changed by the changing step is output as the second shape data.
According to the third aspect of the present invention, the map data generation program classifies a road whose road shape is represented by first shape data representing the road shape by a plurality of points into a straight section and a curved section. Changing the representation of the road shape of the straight section into the first representation and changing the representation of the road shape of the curved segment into the second representation different from the first representation A step of curving, a step of outputting road shape data based on the representation modified by the point train thinning step and the step of curving, as second shape data, and representation by the first representation or the second representation The road shape of the road including the plurality of lanes, the road shape of at least one of the plurality of lanes, the number of lanes of the plurality of lanes, and the road width The lane representation change step of changing to a representation including information, and in the lane representation change step, data of the road shape of the road for at least one lane of the road shapes of the road including the plurality of lanes Is deleted, and in the output step, data of the road shape according to the expression changed in the lane expression change step is output as the second shape data.

  According to the present invention, map data with a small amount of data can be generated.

Schematic diagram of a vehicle control system according to the first embodiment Block diagram showing the hardware configuration of the map data generation device Block diagram showing the functional configuration of the map data generation device A diagram illustrating first shape data Explanatory drawing of shape determination processing by the shape determination unit Explanatory drawing of the point sequence thinning process by the point sequence thinning unit Explanatory drawing of the curving process by the curving unit Explanatory drawing of the lane expression change process by the lane expression change unit Figure illustrating second shape data Flow chart of map data generation process A diagram illustrating first shape data

First Embodiment
FIG. 1 is a schematic view of a vehicle control system 1 according to a first embodiment of the present invention. The vehicle control system 1 includes a map data generation device 3 and a vehicle 5. The map data generation device 3 generates map data 4 for vehicle control by executing map data generation processing described later on the input base map data 2. Base map data 2 is map data including at least information on roads. In the base plan data 2, the shapes of a plurality of lanes (lanes) constituting a road are represented by a plurality of points specified by, for example, latitude and longitude. The vehicle control map data 4 is map data that is created based on the base map data 2 and includes at least information on the road. Although the details will be described later, the vehicle control map data 4 represents a road shape equivalent to the base map data 2 with a smaller amount of data than the base map data 2.

  A vehicle control device 6 is mounted on the vehicle 5. The vehicle control device 6 controls the vehicle 5 based on the vehicle control map data 4 generated by the map data generation device 3. For example, the vehicle control device 6 performs autonomous driving control of the vehicle 5 based on the outputs of various sensors (not shown) mounted on the vehicle 5 and the vehicle control map data 4. The vehicle control device 6 performs autonomous driving control of the vehicle 5 by acquiring road information necessary for vehicle control (for example, acceleration, deceleration, steering, etc.) from the vehicle control map data 4.

  The vehicle control map data 4 is stored in advance, for example, in a storage medium (not shown) of the vehicle control device 6. Alternatively, the vehicle control map data 4 is transmitted from, for example, a server (not shown) to the vehicle control device 6 via a communication channel such as a mobile telephone network.

  FIG. 2 is a block diagram showing the hardware configuration of the map data generation device 3. The map data generation device 3 includes a storage unit 31, an operation unit 32, and a data input / output unit 33.

  The storage unit 31 is, for example, a storage device such as a hard disk drive. The storage unit 31 has a first storage area 311 storing base map data 2 as input data, and a second storage area 312 storing vehicle control map data 4 as output data.

  The data input / output unit 33 has a data input unit 331 and a data output unit 332. The data input unit 331 reads the base map data 2 from the first storage area 311 and inputs the data to the calculation unit 32. The data output unit 332 writes the vehicle control map data 4 output from the calculation unit 32 in the second storage area 312.

  Arithmetic unit 32 executes map data generation processing to be described later on base map data 2 input by data input unit 331, and outputs vehicle control map data 4 to data output unit 332.

  Base plan data 2 includes first shape data 21, lane number data 22, lane width data 23, and road attribute data 24. The first shape data 21 is data indicating the road shape by a plurality of points specified by, for example, the latitude and the longitude. The first shape data 21 includes the shape of each lane for a road including a plurality of lanes. The lane number data 22 is data indicating the number of lanes of the road (the number of lanes). The lane width data 23 is data indicating the width of one lane of a road.

  The road attribute data 24 is data indicating road attributes such as start and end points of branching and merging, start and end points of increasing and decreasing lanes, toll booths, tunnels, lane types, and the like. The road attribute data 24 may include data equivalent to the lane number data 22 and the lane width data 23.

  The vehicle control map data 4 includes second shape data 41, lane number data 42, lane width data 43, and road attribute data 44. The second shape data 41 is data indicating a road shape. Although the details will be described later, the second shape data 41 has an expression format different from that of the first shape data 21 so that the data size is smaller than that of the first shape data 21. The lane number data 42, the lane width data 43, and the road attribute data 44 are the same as the data of the same name included in the base map data 2, so the description will be omitted.

  FIG. 3 is a block diagram showing a functional configuration of the map data generation device 3. The map data generation device 3 includes a shape determination unit 35, a point train thinning unit 36, a curving unit 37, and a lane representation changing unit 38.

  The shape determination unit 35 classifies the road included in the first shape data 21 input to the data input unit 331 into a straight section and a curved section. In other words, the shape determination unit 35 determines a point where the road shape has changed from a straight line to a curve and a point where the road shape has changed from a curve to a straight line, and divides the road at each point.

  Although the details will be described later, even if the shape determination unit 35 includes a plurality of sections having different road attributes even if the section is a continuous straight section and a curved section, the plurality of sections are included. Classify as separate straight and curved sections. In other words, each straight section and the curved section classified by the shape determination unit 35 have a common road attribute. In the present embodiment, road sections having different road attributes are classified as separate straight sections and curved sections.

  The point sequence thinning-out unit 36 executes point sequence thinning-out processing described later on the road shape of the straight section classified by the shape determination unit 35. By the point sequence thinning process, the road shape of the straight section is expressed by a smaller number of points, and the amount of data is reduced.

  The curving unit 37 performs a curving process described later on the road shape of the curved section classified by the shape determination unit 35. By the curving process, the road shape of the curved section is represented by a smaller number of points (control points), and the amount of data is reduced.

  The lane expression change unit 38 executes lane expression change processing, which will be described later, on the road shape data output by the point sequence thinning processing and the curve conversion processing. Road shape data of a plurality of lanes present in one straight section or one curved section is changed to the reference lane representation described later, if possible, by the lane representation changing process. By using the reference lane representation, the amount of road shape data is further reduced. The road shape data changed to the reference lane expression is output to the data output unit 332.

  Hereinafter, map data generation processing executed by the map data generation device 3 will be described with reference to FIGS. 4 to 10. The map data generation process includes the shape determination process by the shape determination unit 35, the point sequence thinning process by the point sequence thinning unit 36, the curve conversion process by the curve conversion unit 37, and the lane expression change process by the lane expression change unit 38. And.

  FIG. 4A illustrates the data structure of the first shape data 21. FIG. 4B illustrates the road shape represented by the first shape data 21. As illustrated in FIG. As shown in FIG. 4A, the first shape data 21 is data including a plurality of points 104 represented by the longitude 101 and the latitude 102. As shown in FIG. 4 (b), each point 104 is located on the center line 107 of each lane 106 included in the road 105. That is, the first shape data 21 is data representing the road shape by representing the center lines 107 of the individual lanes 106 by a plurality of points 104.

  FIG. 5 is an explanatory diagram of the shape determination processing by the shape determination unit 35. The shape determination unit 35 divides the roads included in the base map data 2 into sections having common road attributes. The road 108 in the expressway illustrated in FIG. 5 has five sections, a first section 111, a second section 112, a third section 113, a fourth section 114, and a fifth section 115, from the lower side of the paper to the upper side. Divided into The first section 111 is a straight section of a main road. The second section 112 is a branch start section to a decelerating lane. The third section 113 is a straight section including a decelerating lane. The fourth section 114 is a rampway section heading for the exit. The fifth section 115 is a straight section of the main road. The second section 112 is different from the first section 111 and the third section 113 in that the second section 112 is different from the first section 111 and the third section 113 before and after the point in that the second section 112 includes oblique decelerating lanes. Divided into sections.

  The shape determination unit 35 classifies each section divided based on the road attribute into either a straight section or a curved section. If the whole of one section classified based on the road attribute is classified into one straight section or curved section, one section is further divided into a plurality of sections, each of which is divided into a straight section and a curved section. It may be classified.

  For example, the shape determination unit 35 divides one section into a plurality of portions, and obtains the curvature and the curvature radius for each portion. If the radius of curvature is equal to or greater than a predetermined length (for example, 1000 m), the portion is determined to be linear. If it is less than a predetermined length (for example, 1000 m), it is determined that the portion has a curved shape. If all the shapes in the section are straight, the section is classified into one straight section as a whole. If all the shapes in the section are curves, the section is classified into one curve section as a whole. When the straight line shape and the curved line shape are switched between continuous parts in the section, the shape determination unit 35 divides the section there, and classifies one into a straight line section and the other into a curved section.

  FIG. 6 is an explanatory view of a point sequence thinning process by the point sequence thinning unit 36. The point train thinning unit 36 reduces the volume of road shape data for each road section determined as a straight section by the shape determination unit 35. The point row thinning unit 36 reduces the data volume of the linear shape using, for example, the well-known Douglas-Peuker algorithm or the like. For example, the point sequence thinning unit 36 connects the start point and the end point with a straight line in the shape data of one section, and searches for a point where the distance is the most distant from the straight line. The point row thinning unit 36 measures the distance between a point at which the distance is the greatest and the straight line, and when the distance exceeds a predetermined distance, the point is a point to be left after thinning. Next, the point row thinning unit 36 searches for a point at which the distance is the greatest from the straight line connecting the start point and the above point and the straight line connecting the end point and the above point, and repeats the same processing. When the distance from the straight line at the farthest point becomes equal to or less than the above-described predetermined distance, the point sequence thinning unit 36 ends the point sequence thinning process. As a result, the point train thinning unit 36 can create road shape data after thinning so that the difference from the original road shape in the base map data 2 is within a predetermined distance. The point train thinning unit 36 inputs the road shape data after thinning into the lane expression changing unit 38.

  For example, FIG. 6 (a) schematically illustrates the road section 116 before the point sequence thinning process is applied, and a plurality of points 117a, 117b, 117c, and 117d that constitute the road section 116. . The point 117 a is the start point of the road section 116, and the point 117 b is the end point of the road section 116. FIG. 6B schematically shows the road section 116 after the point train thinning process is applied, and a plurality of points 117a, 117b, and 117c that constitute the road section 116. By thinning out the points 117d that have less influence on the road shape representation, the road section 116 is represented by a smaller number of points than in FIG. 6A.

  FIG. 7 is an explanatory view of a curving process by the curving unit 37. As shown in FIG. The curving unit 37 reduces the volume of road shape data for each road section determined by the shape determination unit 35 as a curved section. The curving unit 37 reduces the volume of road shape data by, for example, Bezier-curved road shape data. The curving unit 37 sets, as shape data of one section, points other than the start point and the end point as control point candidates of the Bezier curve. The curving unit 37 tentatively performs Bezier curve conversion of road shape data with each control point candidate as a control point, and calculates an error from the original road shape data. The curving unit 37 adopts, as a final control point, a control point candidate in which the maximum value of the error is the smallest among all the control point candidates, and converts the road shape data into a Bezier curve. The curving unit 37 divides the road shape data at the middle point of the road section when all the calculated maximum values of the errors are equal to or more than a predetermined value (for example, 1 meter). Re-execute the above-mentioned curving process for each road section. Thus, the curving unit 37 can create road shape data after curving so that the difference from the original road shape in the base map data 2 is within a predetermined value. The curving unit 37 inputs the road shape data after curving into the lane representation changing unit 38. The road shape data may be a parametric curve other than the Bezier curve.

  For example, FIG. 7A schematically illustrates a road section 118 before the curvilinear processing is applied, and a plurality of points 119a, 119b, and 119c constituting the road section 118. The point 119a is the start point of the road section 118, and the point 119b is the end point of the road section 118. FIG. 6B schematically illustrates the road section 118 to which the curvilinear processing has been applied, and the start point 119a, the end point 119b, and the control point 120 of the Bezier curve representing the road section 118. By expressing the road shape by a parametric curve having two control points 120, the road section 118 is expressed with a smaller amount of data than that of FIG. 7A.

  FIG. 8 is an explanatory diagram of a lane expression change process by the lane expression change unit 38. The lane expression change unit 38 specifies, for the road shape data input from the point train thinning unit 36 and the curving unit 37, a road section in which no lanes increase or decrease in the section. The lane representation changing unit 38 changes the road shape data of each of the identified road sections to the reference lane representation described below. For example, in the road section 121 shown in FIG. 8A, the lanes are not increased or decreased. The lane expression change unit 38 sets the leftmost lane 122 in the road section 121 as the reference lane of the road section 121. The lane expression change unit 38 discards the road shape data representing the lanes 123 other than the reference lane, and instead adds the number of lanes and the lane width. As a result, as shown in FIG. 8B, the road section 121 is expressed with a smaller amount of data. That is, the reference lane expression is a road shape expression system using data of the road shape of the reference lane, the number of lanes, and the lane width. The lane expression change unit 38 does not execute the above processing for the road section in which the lanes increase and decrease in the section, and holds the road shape data for all the lanes. The lane expression change unit 38 outputs the road shape data after the above processing as the second shape data 41.

  FIG. 9 is a diagram illustrating the data structure of the second shape data 41. As shown in FIG. The second shape data 41 includes a plurality of road segment data 130 representing one road segment. Each road segment data 130 includes representation type data 131, a curve / straight line flag 132, and shape data 133. The representation type data 131 is data indicating whether the road section is represented by a reference lane representation or a normal representation that is not a reference lane representation. The curve / straight line flag is data indicating whether the road segment is classified as a curve segment by the shape determination unit 35 or classified as a straight segment.

  The shape data 133 is data indicating a specific shape of the road section. The shape data 133 corresponding to the curve section of the reference lane representation includes a start point, an end point, and a control point of a parametric curve representing a road shape for one lane. The shape data 133 corresponding to the straight line section of the reference lane representation includes a plurality of points (including a start point and an end point) representing a road shape for one lane. The shape data 133 corresponding to the curve section of the normal expression includes a start point, an end point, and a control point of a parametric curve that represents the road shape of each lane. The shape data 133 corresponding to the straight section of the normal expression includes a plurality of points (including the start point and the end point) representing the road shape of each lane.

  Note that the data structure of the second shape data 41 exemplified in FIG. 9 is an example, and it is also possible to use the second shape data 41 having a data structure different from this. For example, data of the number of lanes and the lane width may be omitted from the second shape data 41 for a road section represented by the reference lane expression. In this case, the vehicle control device 6 using the vehicle control map data 4 acquires lane number and lane width data not from the second shape data 41 but from the lane number data 42 and the lane width data 43.

  FIG. 10 is a flowchart of map data generation processing. In step S10, the shape determination unit 35 selects one unselected road section. In step S20, the shape determination unit 35 classifies the road segment selected in step S10 into one of a straight segment and a curved segment. If classified into a straight section, the shape determination unit 35 advances the process to step S30. In step S30, the point train thinning unit 36 executes point train thinning processing on the road section classified into the straight line section, and advances the process to step S50. If the road section is classified into a curved section in step S20, the shape determination unit 35 advances the process to step S40. In step S40, the curving unit 37 performs curving processing on the road section classified into the curved section, and the process proceeds to step S50.

  In step S50, the reference lane changing unit 38 determines whether the section selected in step S10 has a certain lane, in other words, for example, it is not a road section where the lane is branched. If the lane has not been converted in the road section, the reference lane changing unit 38 advances the process to step S60. In step S60, the reference lane changing unit 38 changes the road shape data subjected to the point sequence thinning process or the curve conversion process into the reference lane expression.

  In step S70, the map data generation device 3 determines whether or not there is an unselected road section. If an unselected road section remains, the process proceeds to step S10. On the other hand, when all the road sections have been selected, the map data generation process shown in FIG. 10 ends.

According to the embodiment described above, the following effects can be obtained.
(1) The shape determination unit 35 classifies a road whose road shape is expressed by the first shape data 21 that expresses the road shape by a plurality of points 104 into a straight section and a curved section. The point train thinning-out unit 36 changes the road shape of the straight section to the first representation. The curving unit 37 changes the road shape of the curved section to a second representation different from the first representation. The data output unit 332 outputs, as the second shape data 41, data of the road shape according to the expression changed by the point sequence thinning unit 36 and the curving unit 37. Since this is done, it is possible to generate map data with a small amount of data that optimally expresses the road shape.

(2) The lane expression changing unit 38 changes the road shape of the road including the plurality of lanes expressed in the first expression or the second expression into the road shape of at least one lane of the plurality of lanes and the lane of the plurality of lanes Change to a representation that includes information about numbers and road widths. Since this is done, the amount of map data can be further reduced.

(3) When one straight section and one curved section include a plurality of sections having road attributes different from each other, the shape determination unit 35 determines each of the plurality of sections as a plurality of straight sections and a plurality of curved sections. Classified into Since this is done, the amount of map data can be further reduced.

(4) The first expression is an expression in which the amount of data is smaller than the case where the road shape of the straight section is expressed by a plurality of points, and the second expression is more than the case where the road shape of a curved section is expressed by a plurality of points Is also a representation with a small amount of data. Since this is done, the amount of map data can be further reduced.

(5) The first expression is an expression method for expressing the road shape of the straight section by the number of points smaller than the plurality of points included in the first shape data 21. The second expression is an expression system that represents the road shape of a curved section by a parametric curve. The point train thinning unit 36 changes the representation of the road shape of the straight section to the first representation by the point train thinning process. The curving unit 37 changes the expression of the road shape of the curved section to the second expression by curving processing. Since it did in this way, each of a straight line segment and a curve segment can be expressed by the optimal expression system.

(6) The point train thinning-out unit 36 sets the distance between the point trains so that the difference between the road shape of the straight line segment in the first shape data 21 and the road shape of the straight line segment represented by the first expression is within a predetermined amount. Perform a pull process. The curving unit 37 performs curving processing so that the difference between the road shape of the curved section in the first shape data 21 and the road shape of the curved section represented by the second expression is within a predetermined amount. Since this is done, it is possible to generate map data having a desired accuracy and a small amount of data.

  The following modifications are also within the scope of the present invention, and one or more of the modifications can be combined with the above-described embodiment.

(Modification 1)
Shape data different from the first shape data 21 illustrated in FIG. 4A may be handled. For example, as in the first shape data 21 a illustrated in FIG. 11, each point 104 a may include the altitude 103. In this case, the point row thinning unit 36 and the curving unit 37 handle the road section in consideration of the elevation. For example, in the shape data of one section, the point row thinning-out section 36 connects the elevation of the start point and the elevation of the end point by a straight line, measures the height difference from this straight line to the point where the height is most distant If the difference exceeds a predetermined amount, the point is a point to be left after thinning. That is, the point row thinning-out unit 36 thins out so that the difference from the original road shape in the base map data 2 is within a predetermined value, taking into consideration not only the planar distance but also the vertical distance. In the later road shape data, it is determined whether to thin or leave points. The same applies to the curving unit 37.

  Although various embodiments and modifications have been described above, the present invention is not limited to these contents. Other embodiments considered within the scope of the technical idea of the present invention are also included within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Vehicle control system, 2 ... Base map data, 3 ... Map data generation device, 4 ... Vehicle control map data, 5 ... Vehicle, 6 ... Vehicle control device, 21 ... 1st shape data, 35 ... shape determination part, 36: Point row thinning out part, 37: Curved part, 38: Lane expression changing part, 41: Second shape data

Claims (8)

A shape determination unit that classifies a road whose road shape is represented by first shape data representing the road shape by a plurality of points into a straight section and a curved section;
A point sequence thinning unit which changes the representation of the road shape of the straight section to the representation by the first representation;
And a curved section to change the representation of the road shape of the curved section to representation by a different second representation from the first representation,
An output unit that outputs, as second shape data, road shape data according to the expression changed by the point row thinning unit and the curving unit ;
The road shape of a road including a plurality of lanes expressed in the first expression or the second expression, information on the road shape of at least one lane of the plurality of lanes, the number of lanes of the plurality of lanes, and the road width And a lane expression change unit for changing the expression to
The lane expression changing unit deletes data of the road shape of the road for at least one lane of the road shapes of the road including the plurality of lanes,
The said output part is a map data generation apparatus which outputs the data of the road shape by the expression changed by the said lane expression change part as said 2nd shape data . In the map data generation device according to claim 1 ,
The shape determination unit, when one of the straight sections or one of the curved sections includes a plurality of sections having different road attributes, each of the plurality of sections may be divided into a plurality of the straight sections or a plurality of the plurality of sections. Map data generation device that classifies into curved sections. In the map data generation device according to claim 2 ,
The first expression is an expression having a smaller amount of data than the case where the road shape of the straight section is expressed by the plurality of points,
The map data generation device according to claim 2, wherein the second expression is an expression having a smaller amount of data than the case where the road shape of the curved section is expressed by the plurality of points. In the map data generation device according to claim 3 ,
The first representation expresses the road shape of the straight section by a number of points smaller than the plurality of points,
The second expression represents the road shape of the curved section by a parametric curve,
The point sequence thinning unit changes the representation of the road shape of the straight section to the first representation by a point sequence thinning process.
The map data generating device, wherein the curving unit changes a road shape representation of the curved section to the second representation by curvilinear processing. In the map data generation device according to claim 4 ,
The point sequence thinning-out unit is configured such that a difference between a road shape of the straight section in the first shape data and a road shape of the straight section represented by the first expression is within a predetermined amount. Do thinning process,
The curving unit performs the curving processing such that a difference between a road shape of the curved section in the first shape data and a road shape of the curved section represented by the second expression is within a predetermined amount. Map data generation device to do. In the map data generation device according to claim 5 ,
The first shape data includes information on the elevations of the plurality of points,
The point row thinning-out unit has a difference between a road shape in the vertical direction of the straight line section in the first shape data and a road shape in the vertical direction of the straight line section represented by the first expression within a predetermined amount Perform the point sequence thinning process to be
The curving unit is configured such that a difference between a road shape in the vertical direction of the curved section in the first shape data and a road shape in the vertical direction of the curved section represented by the second expression is within a predetermined amount. Map data generating device that performs the curve conversion process on A shape determination step of classifying a road whose road shape is represented by first shape data representing the road shape by a plurality of points into a straight section and a curved section;
A point train thinning step of changing the representation of the road shape of the straight section into the representation by the first representation;
A curving step of changing the representation of the road shape of the curved section into a second representation different from the first representation;
An output step of outputting, as second shape data, road shape data according to the expression changed by the point row thinning step and the curving step;
The road shape of a road including a plurality of lanes expressed in the first expression or the second expression, information on the road shape of at least one lane of the plurality of lanes, the number of lanes of the plurality of lanes, and the road width And changing the lane expression to the expression including
In the lane expression change step, data of the road shape of the road is deleted for at least one lane of the road shapes of the road including the plurality of lanes,
Wherein in the output step, maps data generation method for outputting data of a road shape by altered expression by the lane representing changing step as said second shape data. A shape determination step of classifying a road whose road shape is represented by first shape data representing the road shape by a plurality of points into a straight section and a curved section;
A point train thinning step of changing the representation of the road shape of the straight section into the representation by the first representation;
Changing the representation of the road shape of the curved section into a second representation different from the first representation;
Outputting the data of the road shape according to the expression changed by the point sequence thinning step and the curving step as second shape data;
The road shape of a road including a plurality of lanes expressed in the first expression or the second expression, information on the road shape of at least one lane of the plurality of lanes, the number of lanes of the plurality of lanes, and the road width And causing the computer to execute a lane expression change step of changing the expression to
In the lane expression change step, data of the road shape of the road is deleted for at least one lane of the road shapes of the road including the plurality of lanes,
Wherein in the output step, maps data generation program to output the data of the road shape by altered expression by the lane representing changing step as said second shape data.

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