8 Points to Keep in Mind When Creating CAD for 2D Road Register Attached Maps

Table of Contents

• Purpose of creating 2D road ledger drawings in CAD

• Item 1: Fix the creation scope and drawing specifications at the outset

• Item 2: Standardize the assumptions for the coordinate system and scale

• Item 3: Separate layers for road boundary lines and centerlines

• Item 4: Standardize the notation rules for width and length

• Item 5: Determine display criteria for structures and appurtenances

• Item 6: Be careful in handling existing drawings and scanned drawings

• Item 7: Reconcile field survey results with ledger records

• Item 8: Organize data with updates after delivery in mind

• Common mistakes in CAD creation and how to prevent them

• Summary

Purpose of creating 2D road register attached maps with CAD

The purpose of creating 2D road ledger attached drawings in CAD is to organize the position and management extent of roads into easy-to-read plan views and to produce materials that are practical for use in tasks such as road management, construction consultations, occupancy verification, development consultations, boundary confirmation, maintenance and repair, and disaster response. The road ledger organizes management information such as route name, start point, end point, length, width, road area, and structures, but there are situations where it is difficult to grasp on-site positional relationships from text and numbers alone. Therefore, road boundary lines, road centerlines, road edges, width change points, side ditches, bridges, retaining walls, intersection shapes, surrounding features, and the like are drawn in CAD so that practitioners can verify them under the same assumptions.

The advantages of creating drawings in CAD are that lines and text are easy to edit, information can be managed by separating layers, and it is easier to accommodate future updates. With only paper drawings or image materials, road boundary lines, centerlines, structures, annotations, and background information tend to be mixed together, making revisions and verification time-consuming. If organized as CAD data, it becomes easy to check only the road boundary lines, display only the centerlines and widths, or manage structures as separate information.

On the other hand, creating a drawing in CAD does not automatically produce an accurate road ledger map. If the accuracy of the source materials, the coordinate system, the scale, the drawing rules, the basis for the road area lines, consistency with field survey results, or cross-checking with the ledger records are insufficient, the drawings may look neat but be difficult to use in practice. In particular, when digitizing by tracing paper drawings into CAD or when creating road area lines based on existing reference maps, it is necessary to carefully verify the meaning and basis of the lines.

When creating CAD drawings for 2D road register maps, it is important not simply to draw the shape of the road but to produce data that can be used later as road management information. By deciding up front which lines denote the road boundary, which lines are centerlines, what the width represents, how far structures should be shown, which coordinate system to align with, and how to record update history, you can reduce post-delivery corrections and oversights.

In this article, we explain eight items to watch for when creating 2D road ledger attached drawings in CAD, aimed at practitioners. By sequentially confirming, from clarifying the assumptions for CAD creation through coordinates, layers, road width, structures, existing drawings, field surveys, and post-delivery update management, you can improve the quality of the road ledger attached drawings and make it easier to prevent rework in later stages.

Set the scope of work and drawing specifications first as Item 1

When creating a two-dimensional road ledger attached drawing in CAD, the first thing to pay attention to is fixing the creation scope and drawing specifications. If the target area or displayed items change after work has begun, it will affect layer configuration, drawing division, annotations, file structure, and delivery format, increasing the amount of rework. In CAD production, before you start drawing lines, you need to clarify which roads, over what extent, and to what level of information will be represented.

Within the scope, confirm the route name, route number, starting point, end point, target section, intersection areas, branch lines, connecting roads, and drawing boundaries. Maps attached to the road ledger are often organized on a route-by-route basis, but actual roads connect to intersections and adjacent roads. If you extract and map only the target route, there may be awkward points in the connections to adjacent drawings and in the organization of intersection areas.

In the drawing specifications, confirm the scale, sheet size, drawing number, drawing frame (title block), orientation, legend, text size, line types, layer structure, coordinate system, and delivery format. How the data is created varies depending on whether the drawing is produced for viewing, as updatable CAD data, or with the assumption of linking to ledger records and attribute information. If it is for viewing only, visual clarity is prioritized; if updates are anticipated, organizing layers and attributes becomes important.

You also need to decide in advance what will be displayed. Decide how far to go in showing items such as road area boundary lines, road centerlines, road edges, widths, lengths, start and end points, intersection geometry, gutters, catch basins, bridges, retaining walls, slopes, guardrails, signs, lighting, sidewalks, adjacent waterways, boundary-related lines, background features, and so on. Adding more information can make the drawings more useful in practice, but they can also become cluttered. It is also necessary to judge which information to display on the drawing and which to manage as separate documents or attribute information.

Also, organizing how out-of-scope areas and uncertain information are handled will help prevent misunderstandings later. For sections where boundary documents are lacking, sections where on-site verification has not been performed, sections where adjacent roads are managed separately, and structures shown for reference only, take care that they do not appear as confirmed information on CAD drawings. If you deliver without explicitly indicating unconfirmed locations, users may later mistakenly treat them as confirmed information.

Fixing the scope of work and the drawing specifications at the outset is the foundation of the entire CAD creation process. If you proceed while these remain ambiguous, you will face not only corrections to lines and text but also redoing the drawing’s overall layout. By establishing the specifications up front, it becomes easier to balance work efficiency and the quality of the deliverables.

Unify the assumptions about coordinate systems and scale as Item 2

The second point to note is to make the assumptions about the coordinate system and scale consistent. When creating a two-dimensional road ledger map in CAD, it is important to ensure that the positional information on the drawing matches the on-site survey results and related documents. If you draft without clear assumptions about the coordinate system and scale, discrepancies will occur when overlaying road boundary lines, centerlines, and structure locations with other data.

The first thing to confirm is which coordinate system the CAD data will be created in. The way positions are handled varies by source—plane rectangular coordinate system, latitude/longitude, local coordinates, or a drawing’s own coordinates. When overlaying field survey results, as-built drawings, existing attached drawings, documents related to parcel numbers, aerial photographs, point cloud data, and so on, you must verify the differences in coordinate systems.

Even when existing CAD data is available, its coordinates may not be correct. In past work, elements may have been moved or rotated to match appearances, coordinates may not have been assigned if someone simply traced paper drawings, or the data may have been created in a local coordinate system. When inheriting existing data, you need to verify the coordinate system, origin, scale, and the basis for alignment.

Care must also be taken regarding scale. Because scaling up and down is easy in CAD, if you draft based on appearance alone, the scale of the drawing frame, the drawing units, and the appearance when printed can become misaligned. Confirm what one unit on the drawing represents and whether the scale of the drawing frame and annotations matches the scale of the actual data. When converting paper drawings to CAD, it is also important to ensure that the scan image’s scale has been properly corrected.

When creating CAD drawings using paper plans or image materials as a background, treat the images as if they may be distorted. Paper expansion or contraction, tilt during scanning, image resolution, and line thickness can cause the background image itself to not match the actual site. Simply tracing road boundary lines based on the background image will not produce accurate coordinate information. As needed, cross-check with control points and field survey results, and make clear which areas will be used as references.

Assumptions about the coordinate system and scale also affect updates after delivery. If you plan to overlay future on-site survey results or as-built drawings onto the CAD data created this time, you need to be mindful of coordinate consistency from the start. CAD data with an unknown coordinate system will require considerable effort to correct or update later.

When producing CAD drawings of 2D road ledger-attached maps, it is important not only to create well-presented drawings but also to ensure the conditions necessary for using them as positional information. If you record the coordinate system, scale, drawing units, alignment method, and any accuracy-related notes, staff who use the drawings later can make decisions with confidence.

As Item 3, separate the road boundary lines and the centerline into layers

The third point to note is to clearly separate the layers for road boundary lines and centerlines. In CAD drafting, layer management greatly affects the quality of drawings and their ease of updating. If road boundary lines, road centerlines, road edges, structures, boundary-related lines, annotations, and background features are mixed on the same layer, verification and modification become difficult.

Road boundary lines are important lines that indicate the extent managed as a road. The road centerline connects a route's starting point to its end point and serves as an axis for organizing length, stationing, construction sections, and inspection points. Both are core pieces of information in the maps attached to the road register, but their meanings differ. If they are treated as the same line type or placed on the same layer, people using the drawings may misinterpret them.

In the road area line layer, it is important to clarify the meaning and basis of each line. If you can manage whether a line is based on land acquisition documents or boundary documents, inherited from existing attached maps, or reflects the results of on-site surveys, later verification becomes easier. Treating lines with different bases in the same way makes it difficult to determine how much they can be trusted during updates.

In the centerline layer, make it easy to check the continuity of each route. Verify that centerlines are not interrupted midway, do not bend unnaturally at intersections, and are correctly connected at their start and end points. Because centerlines relate to length and attribute information, it is important not to treat them as mere auxiliary lines but to organize them as the axis for road management.

Edges of the road, pavement edges, and gutter edges should be managed separately from the road boundary line. Even if a line visible on site appears to be the edge of the road, it does not necessarily coincide with the road boundary line. If pavement edges or gutter edges are placed on the same layer as the road boundary line, someone who later reviews the drawings may become confused. The road boundary, existing road edge, structure edges, and boundary-related lines should each be separated so that their meanings are clear.

We will also standardize layer names to be easy to understand. Instead of abbreviations or temporary names that only the creator understands, we will use names that a person reviewing them later can understand. When multiple people are working together or updates are made after delivery, inconsistent layer names make it easy for corrections to be overlooked or for accidental edits to occur.

The purpose of separating layers is not just to organize appearance. It is to streamline tasks such as displaying only the road boundary lines to check them, extracting only the centerlines to verify their lengths, updating only structures, or editing only annotations. If CAD data are to be used long-term as road management documentation, layer design needs to be done carefully from the very beginning.

Standardize the notation rules for width and length as Item 4

The fourth point to note is to standardize the notation rules for width and length. In two-dimensional road ledger attached maps, width and length are frequently referenced in practice. Because they are used for construction design, occupancy consultations, development consultations, road-access confirmation, maintenance and repairs, ledger updates, and so on, ambiguous notation can lead to misunderstandings by reviewers and users.

Regarding width, first clarify which width is being displayed. Road area width, effective width, carriageway width, and paved width are not the same. Road area width indicates the width of the area managed as a road and may include drainage ditches, shoulders, sidewalks, and slopes. Effective width may be treated as the width actually available for passage or use. Carriageway width and paved width are further distinct concepts.

If you simply label "width" on a CAD drawing, users may find it difficult to determine what it refers to. As a drawing specification, standardize the definitions of the widths to be displayed and explain them in notes where necessary. When dealing with multiple types of widths, separate layers and notes so that road area width and reference widths are not mixed.

Marking the points of width change is also important. A road does not have the same width along its entire length. Widths change at intersections, bridge sections, sections where sidewalks are installed, narrow sections, lay-bys, and at the boundaries between improved and unimproved road sections. In CAD drawings, width values must be placed so that it is clear which section they correspond to. If a note is placed in a position where it appears to belong to a different section, it can cause misreading.

For length, confirm the relationship between the centerline, the start point, and the end point. Clarify whether the length is based on the centerline or is the length as a management section, and how intersection areas are to be treated. If the centerline is modified, confirm whether this affects the length values. If the length in the register records does not match the centerline length in CAD, the measurement conditions and update history need to be checked.

Unify font sizes and unit notations. If the notation methods differ between drawings, the overall consistency of the deliverables will be lost. Standardizing the units for width and length, the number of digits, the placement of annotations, and the use of symbols will make the drawings easier to review. When creating multiple drawings, it is important to apply the same rules across all drawings.

Width and length may seem easy to handle because they appear as numeric values, but in practice the definitions and measurement conditions are important. By standardizing notation rules when creating CAD and cross-checking with ledger records and field survey results, you can reduce requests for corrections after delivery and misunderstandings in practice.

Establish display standards for structures and appurtenances as Item 5

The fifth point to note is to establish display standards for structures and road appurtenances. In 2D road ledger attached maps, not only road boundary lines and centerlines but also facilities such as gutters, catch basins, transverse drains, bridges, retaining walls, slopes, guardrails, signs, lighting, sidewalks, and curbs may be shown. These are important pieces of information related to road management and construction planning, but if the display standards are ambiguous, the drawings can become difficult to read or may omit necessary information.

The first thing to decide is which structures to display. The required display content varies depending on the purpose of using the map attached to the road ledger—whether it is for managing road areas and centerlines, for supporting maintenance and on-site inspections, or as basic reference data for construction consultations. Displaying all facilities in detail can increase the amount of information and make the drawings overcrowded. Conversely, omitting too many important structures can make the maps difficult to use in practice.

Side gutters, catch basins, and cross drains are facilities that are commonly depicted because they relate to road drainage and construction planning. When creating drawings in CAD, you must decide whether to represent the inside or the outside of a gutter, and whether to indicate a basin by its center point or by its outline. If the display method varies from drawing to drawing, users may misunderstand the locations.

Bridges, retaining walls, and slopes are related to the road area and management boundaries. In bridge sections, the treatment of the road width and the centerline may differ from adjacent sections. Retaining walls and slopes may be included within the road area, or they may be involved in the interface with adjacent land. In CAD, drawings are organized so that they not only show the locations of structures but also make clear their relationships to the road boundary lines and the centerline.

It is also necessary to consider separating roadside fixtures into those to be displayed and those to be managed in separate documents. If all items such as signs, guardrails, lighting, and wheel stops are shown on the drawings, road boundary lines and width annotations can become difficult to read. One method is to display the main facilities on the drawings and organize the details in attribute information or management documents.

Structures and ancillary items are prone to discrepancies between the site and the documentation. Facilities shown on old as-built drawings may have been removed, and facilities newly installed on site may not be reflected in existing attached drawings. When creating CAD, compare not only existing records but also, as necessary, the results of on-site verification. It is important to keep organized the items that exist on site but are not on the drawings, and the items that are on the drawings but not present on site.

When drawings are produced without established display standards, the way elements are represented varies by drafter. If the layers, line types, symbols, notes, and display ranges for structures are standardized, the overall readability of the drawings improves and it becomes easier to perform updates. Display standards for structures and appurtenances are indispensable elements for stabilizing the quality of CAD production.

Item 6: Pay attention to the handling of existing drawings and scanned drawings

The sixth point to note is the handling of existing drawings and scanned drawings. When creating CAD for 2D road ledger attached maps, work often relies on past road ledger attached maps, paper drawings, construction drawings, survey maps, boundary materials, and other sources. These materials are important references, but they cannot necessarily be used as accurate CAD data as-is.

Scanned images of paper drawings are convenient for visual inspection, but they are affected by paper expansion and contraction, creases, stains, skewing during scanning, image distortion, insufficient resolution, and other factors. When tracing over an image as a background in CAD, there is a risk of transferring the original image's distortions directly into the lines. Especially when handling roadway boundary lines or lines near boundaries, it is important not to rely solely on the scanned drawings.

Existing CAD data should not be trusted blindly. CAD drawings created in the past may lack coordinates, use custom coordinate systems, have positions adjusted for display, or contain lines left over from work in progress. Layer names can be inconsistent, and road boundary lines and reference lines may be mixed together. When using existing CAD data, verify the layers, coordinates, creation date, revision history, and supporting documentation.

When using existing drawings, confirm whether they are the latest version. Drawings from before road improvements, interim verification drawings during construction, as-built drawings after completion, and drawings after ledger updates may be mixed together. Proceeding with CAD creation based on old drawings can produce results that do not match the actual road geometry, widths, or locations of structures on site. It is necessary to verify not only the drawing name and update date but also that the content is consistent with the actual site.

When aligning scanned drawings, use reference points or known points to verify over what area and to what degree they match. Even if some points coincide, the entire drawing may not align. When producing road ledger maps covering a wide area or joining multiple drawings, be mindful of distortions in individual drawings and misalignments at the connections.

When converting existing drawings into CAD by tracing them, it is also important to verify the meaning of the lines. On older drawings, road area boundary lines, road edges, parcel boundaries, structure lines, and reference lines may be depicted in similar ways. If you trace without confirming the meanings of the lines, you may end up treating an incorrect line as a road area boundary line.

Existing drawings and scanned drawings are useful materials for improving work efficiency, but they must be used after confirming their accuracy and meaning. In CAD creation, it is important to understand the limitations of the source materials and, when necessary, verify them against ledger records, on-site survey results, as-built drawings, and boundary documents.

Item 7: Cross-check on-site survey results with registry records

The seventh point to note is to cross-check the field survey results with the ledger records. When creating CAD drawings for 2D road ledger attached maps, the CAD drawings must match both the field survey results and the ledger records. Even if the alignment looks neat visually, if it contradicts the field survey results or the ledger records, problems will arise when used in practice.

When using field survey results, confirm the meaning of each measured point. If you cannot determine what was measured — road edge, pavement edge, outside of a gutter, boundary marker, curb, manhole, retaining wall, a point on the centerline, a point where the width changes, etc. — you will not be able to correctly reflect it in the CAD drawing. Rather than importing only the coordinate values, organize the point name, the measured feature, the measurement date, the measurement method, and the correspondence with site photographs.

If the survey results do not match the existing attached map, identify the cause. Determine whether the existing map is outdated, whether the paper drawing is distorted, whether road improvements have not been reflected, whether the measurement target differs, or whether the coordinate system is different. A discrepancy does not necessarily mean you should simply adjust everything to match the survey results. Road area boundary lines relate to land acquisition and boundary documentation, and centerlines relate to ledger management, so each line must be judged individually.

When reconciling with the ledger record, we confirm the route name, starting point, end point, length, width, road area, and structure information. On the CAD drawings we check whether the centerline length on the CAD drawing matches the length in the ledger record, whether the width shown conflicts with the ledger’s width, and whether the start and end points are clearly identifiable on the drawing. Because sometimes only the ledger record is updated while the drawing remains outdated, or vice versa, it is necessary to check both.

There can also be discrepancies between on-site survey results and registry records. If the pavement width measured in the field differs from the road area width shown in the registry, it may not be an error but a difference in the definition of width. Distinguish between road area width, effective width, carriageway width, and pavement width, and clarify which value to display on CAD drawings.

When creating CAD drawings, it is useful to make it possible to distinguish areas where survey results have been reflected from areas that inherit existing materials. If the entire section has not been surveyed on site, some sections may be upgraded to higher accuracy while the surrounding areas remain as the existing drawings. In this case, if differences in accuracy are not managed, users may mistakenly assume that the entire drawing has the same level of accuracy.

Reconciling on-site survey results with ledger records is an important process for linking CAD drawings to both the field and management information. By achieving both field accuracy and ledger consistency, the practical value of 2D road ledger maps increases.

Organize data as Item 8 with an eye toward post-delivery updates

The eighth point to note is to organize CAD data with post-delivery updates in mind. 2D road ledger maps are not documents that are finished once created. They will continue to be updated in response to road improvements, side gutter repairs, sidewalk development, occupancy works, development attribution, disaster recovery, boundary confirmation, and so on. Therefore, it is important to configure the data structure at the time of creation so that it can be easily updated.

To make CAD data easy to update, organize the layer structure, line types, annotations, attributes, file names, drawing numbers, and revision history. If road boundary lines, centerlines, road edges, structures, annotations, and background information are properly separated, you can edit only the necessary parts when updating in the future. If everything is consolidated into a single layer, there is a risk of inadvertently modifying unrelated lines during revisions.

The distinction between the official version, the working version, and past versions is also important. When updating after delivery, if you cannot tell which data is the official version, you may end up revising based on an old drawing. Record the creation date, the update date, and the version status in the CAD data file name, in the title block within the drawing, and in the revision history.

In the update history, record which document was used as the basis and which parts were modified. Make it clear whether the road boundary line was updated, the centerline was corrected, width annotations were changed, or structures were added. Without a history, you will not be able to trace the basis for lines or numerical values during the next update.

Unverified areas and reference markings will also be organized. Areas where on-site confirmation has not been performed, locations with insufficient boundary documentation, and places where existing drawings have been carried over unchanged will be indicated with notes or management documents as necessary. Presenting undetermined information as if it were confirmed may cause users to make incorrect decisions after delivery.

The delivery format also affects maintainability. Providing only view-only data can make future revisions difficult. If updates are anticipated, organizing editable CAD data, layer structures, a list of related documents, correspondence with ledger records and reports, coordinate information, and on-site verification records will make the data more practical and easier to use in day-to-day work.

When creating CAD drawings for 2D road ledger maps, it's important to consider not only how they will look upon completion but also how they will be operated and maintained in the future. If the data is made easy to update, it will reduce rework in road management operations and result in road ledger maps that can be used over the long term.

Common Mistakes in CAD Creation and How to Prevent Them

There are several typical mistakes when creating CAD drawings for 2D road ledger-attached maps. The most common is confusing road area lines, road edges, boundary lines, and structure lines. If on-site pavement edges or gutter edges are treated as road area lines, the drawings may not match land acquisition documents or boundary records. To prevent this, it is important to confirm the meaning of each line and to separate layers and legends.

Next, there is an error of drafting without checking the coordinate system. If you create drawings by visually aligning existing drawings or scanned images, misalignments will occur when overlaid with field survey results or other spatial information. At the start of work, confirm the coordinate system, scale, drawing units, and alignment method, and, if necessary, verify them with control points or survey results.

Annotation errors for width and length are also likely to occur. For example, confusing the road area width with the pavement width, annotating width values in positions where it is unclear which section they correspond to, or correcting the centerline but failing to review the length. Widths and lengths should be checked together with the ledger records, the centerline, and the road boundary lines.

Mistakes can also occur from tracing existing drawings as-is. Older paper drawings or scanned drawings may not match current site conditions in terms of their creation date or accuracy. The shape after road improvements may not be reflected. When using existing materials, verify the creation date, revision history, and consistency with the site conditions.

Omissions in indicating structures can also cause practical problems. If side ditches, manholes, bridges, retaining walls, or guardrails are not consistent with the site or the as-built drawings, construction planning and maintenance will be affected. It is important to decide which structures to display at the outset and to reconcile that list with on-site verification results and related documents.

Finally, creating data without considering post-delivery updates is also a major mistake. If layers are not organized, file names are hard to understand, there is no update history, and working versions and final versions are mixed together, future updates will require extra work. It is important to organize CAD drawings not only for delivery but as materials that will be continually updated.

To prevent these mistakes, it is effective to incorporate steps such as pre-work specification checks, document checks, coordinate verification, layer design, intermediate checks, and pre-delivery checks into the workflow. Creating CAD drawings may look like the task of drawing lines, but in reality it is the task of organizing road management information. By checking both the appearance of the drawings and the content of the data, you can improve the quality of the deliverables.

Summary

When creating CAD drawings for two-dimensional road register attached maps, it is important not only to consider drawing speed and the neatness of appearance but also to ensure the accuracy and updatability required for use as road management materials. By considering road boundary lines, centerlines, widths, lengths, structures, coordinates, existing documents, field survey results, and post-delivery update management as an integrated whole, you can produce road register attached maps that are practical and easy to use in actual operations.

The first thing to pay attention to is to finalize the scope and drawing specifications. If you clearly define the target route, start point, end point, intersections, branch lines, display items, and delivery format, you can more easily avoid major revisions in the later stages of the work.

Next, unify the assumptions about the coordinate system and scale. Even if a drawing looks tidy in CAD, if the coordinate system or drawing units are unclear, discrepancies will occur when it is overlaid with field survey results or related data. When using paper drawings or scanned drawings, you must also consider the distortion of the original source material and the limits of its accuracy.

Separating layers for road boundary lines and centerlines is also important. By managing road boundary lines, centerlines, road edges, structure lines, and reference lines separately, you can prevent misinterpretation of drawings and make future updates easier. It is important to prepare layer names and a legend that clearly convey the meaning of each line.

Notation rules for width and length also need to be standardized. Avoid confusing road area width, effective width, carriageway width, and pavement width, and make clear which measurements correspond to which sections. If the centerline or the start/end points are revised, also verify consistency with the length and with ledger records.

Decide in advance on display standards for structures and appurtenances as well. If you organize how extensively to display features such as side ditches, manholes, bridges, retaining walls, guardrails, signs, and lighting, which layer to manage them on, and how to reconcile them with on-site conditions and related documents, it will be easier to balance drawing clarity and practical usability.

Existing drawings and scanned drawings are useful materials, but it is risky to treat them as accurate CAD data as-is. You should verify the creation date, revision history, coordinates, the meaning of lines, and consistency with the actual site, and, where necessary, cross-check them against survey results and ledger records.

Cross-checking the field survey results with the ledger records is also indispensable. By confirming what the survey points indicate and whether the widths and lengths in the ledger match the CAD drawings, you create a road ledger attachment map that is consistent with both the field and the management information.

Finally, organize the CAD data with post-delivery updates in mind. Organizing layers, file names, drawing numbers, revision history, the distinction between final and working versions, and the management of unconfirmed items will make it easier to accommodate updates after road improvements or on-site verification.

To advance the CAD creation of two-dimensional road ledger-attached maps more reliably, it is effective to link accurate position information acquired on site to the CAD data. LRTK, a high-precision GNSS positioning device that can be attached to an iPhone, is a suitable option for work that involves confirming on-site features such as road areas, centerlines, points of width change, gutters, manholes, boundary markers, and structure locations and recording them as high-precision position information. If you want to improve the accuracy of two-dimensional road ledger-attached maps by cross-checking on-site position information rather than judging solely from existing materials during CAD creation, considering the use of LRTK can help reduce revision requests and streamline road management operations.