Explaining the Procedure for Creating 2D Road Ledger Attached Maps in 7 Steps

Maps attached to the road ledger are important drawings that organize, in plan view, road zones, widths, boundaries, structures, encroachments, ancillary facilities, and other elements necessary for road management. Among these, two-dimensional maps attached to the road ledger serve as basic reference materials that are routinely consulted by road managers, surveyors, designers, maintenance personnel, and practitioners involved in occupancy consultations.

However, when it actually comes to creating them, it is easy to become unsure about which documents to collect, what to acquire during field surveys, which information should be reflected on the drawings, and how far the deliverables should be prepared. Road ledger maps are not merely road plan views; they are drawings that organize and overlay management information under the Road Act, actual on-site conditions, past survey results, boundary data, occupancy information, and so on. Therefore, if the preparation procedure is mistaken, rework can occur in later stages, and the outputs may become difficult to use for confirming road limits, obtaining occupancy permits, designing construction works, and for maintenance and management.

This article explains, in seven steps, the workflow from preparation to deliverable verification for practitioners responsible for creating 2D road ledger maps. To help those handling this for the first time grasp the overall picture, it organizes, in order, the approach to creation, the information that should be checked, and key points to prevent mistakes.

Table of Contents

• What does a 2D road ledger map represent?

• Step 1 Confirm the scope of the work and the objectives for road management

• Step 2 Collect existing materials and reference information

• Step 3 Obtain necessary information through field surveys and measurements

• Step 4 Organize road area and boundary information

• Step 5 Depict road structures and ancillary facilities on the drawings

• Step 6 Refine drawing representation and attribute information

• Step 7 Conduct verification checks and organize deliverables

• Common mistakes and prevention measures in creating 2D road ledger maps

• Summary To make a usable road ledger map, field accuracy and ease of updating are important

What does a two-dimensional road ledger attached map represent?

A two-dimensional road ledger attachment map is a drawing that organizes, in plan view, the area, alignment, width, boundaries, structures, ancillary facilities, and occupancies of roads managed by the road administrator. It is generally treated as part of the road ledger and is referenced in situations such as road management, construction planning, occupancy consultations, boundary verification, maintenance and repairs, disaster response, and on-site inquiries.

There are parts that resemble a typical road plan view, but road ledger maps place emphasis on information necessary for road management. For example, it is important to record on the drawing not only the shapes of the carriageway and sidewalks but also road boundary lines, public–private boundaries, gutters, retaining walls, slopes, bridges, culverts, street trees, lighting, signs, and road occupancies—features that are meaningful for management. Rather than simply creating a drawing that looks neat, the drawing must allow a third party later to confirm the road’s condition and the scope of its management.

The term "two-dimensional" means representing positional relationships on a plane. Unlike three-dimensional models or point cloud data that include height information, two-dimensional road register maps depict the shape of roads as viewed from above using lines, symbols, text, and annotations. They make it easy to understand road length, width, zones, and facility locations, and are characterized by being easy to use as paper drawings or common drawing data.

On the other hand, precisely because these are two-dimensional drawings, selecting which information to show and unifying how it is depicted are important. Although many structures and facilities exist on site, drawing everything with the same visual weight makes the drawings difficult to read. Priority should be given to the information required for the maps attached to the road ledger, and the drawings should be organized so that the road area, centerline, boundary lines, width, major structures, encroachments, and management-related notes are easily distinguishable.

Also, maps attached to the road ledger are not finished once they are created. The condition of roads changes due to road improvement works, pavement repairs, sidewalk construction, side gutter repairs, the installation or removal of encroachments, and boundary determinations. Therefore, it is important not only to ensure accuracy at the time of creation but also to structure the data so it can be easily updated in the future. By organizing the drawing's layer structure, feature classification, annotation methods, and correspondence with survey results, you can greatly reduce the effort required for the next update.

Step 1: Confirm the scope of the work and the objectives for road management

The first thing to do when creating a 2D road ledger map is to confirm the target area and purpose. The workload and the content of the deliverables for a road ledger map can vary greatly depending on the section to be covered, the scale, the extent of what is represented, and the information required. Rather than jumping straight into drawing plans or conducting field surveys, you should first clarify what it is for, what area it will cover, and to what level of accuracy it will be organized.

The scope varies depending on the purpose of the work and may include an entire route, a section, areas around intersections, planned road improvement areas, and areas targeted for maintenance and management. When organizing this as a road register, consistency with the route number, the designated route name, the starting point, the end point, and the managed length is important. When preparing it in connection with construction or occupancy negotiations, it may be necessary to confirm not only the subject road but also adjacent roads, intersecting roads, connecting waterways, private property boundaries, and the locations of existing encroachments.

In confirming the objective, distinguish whether you are simply creating drawings, updating existing drawings, clarifying road boundaries, or resolving discrepancies between the field and the registry. The materials required and the points to check differ between new creation and update work. If updating existing drawings, it is important to identify the changed areas and verify the differences from past drawings. If creating new drawings, you need to decide from the outset the survey control, drawing specifications, feature classification, and deliverable formats.

The scale and how drawings are used should be confirmed early on. Maps attached to the road ledger can serve multiple purposes, such as viewing, consultation, management, and editing. When intended for paper output, text size, line types, annotation density, and the coverage of split sheets are important. When intended for on-screen viewing and internal sharing, organizing drawing data layers and assigning searchable attributes are important.

A common mistake at this stage is to start work while the scope of what is to be produced remains unclear. For example, if you assume you only need to整理 the roadway boundary lines and later discover that ditches, encroachments, boundary points, and road widths are also required, the field survey will have to be redone. Also, treating intersections or connection points to private land as out of scope can cause the drawings to lose continuity. It is important to indicate the scope with lines on the drawings and confirm a shared understanding among stakeholders before moving on to the next task.

Step 2 Collect existing documents and reference information

When the scope and purpose have been determined, next gather existing documents and reference information. A two-dimensional road register map is not created by field surveying alone. It is produced by cross-checking multiple sources of information, such as past road registers, designated route documents, land acquisition maps, cadastral maps, boundary confirmation records, as-built drawings, occupancy registers, aerial photographs, topographic maps, and control point results.

First, the items to check are the existing road ledger attached maps and road ledger records. If a ledger already exists, confirm the route name, route number, start and end points, length, width, road area, management classification, and so on. Old drawings may not match current on-site conditions, but they provide clues to understand the history of road management. Do not ignore drawings just because they are old; treat them as material for identifying where they differ from the current situation.

Next, check the materials related to boundaries and land parcels. To correctly draw the road boundary line, information such as the boundary between the road right-of-way and private land, the extent of public land, past land-acquisition lines, and boundary determination points is important. In areas where cadastral surveys have been completed, verify consistency with cadastral maps and coordinate results. In areas where cadastral surveys have not been conducted, judgments will be made by combining old public maps, land maps, boundary confirmation documents, and the locations of existing field stakes.

As-built drawings are also important documents. Completion drawings for road improvements, sidewalk installations, side ditch repairs, pavement replacement, and intersection improvements may show the dimensions and positions of structures as reflected on site. However, completion drawings do not necessarily match current conditions. Additional work may have been carried out after completion, or structures may have been altered during maintenance and repairs, so they need to be used in combination with on-site verification.

Documents related to encroachments should not be overlooked. Within the road there are many facilities, such as utility poles, communications poles, underground conduits, manholes, sign posts, guardrails, and lighting poles. Because facilities managed by the road administrator and facilities managed by occupiers are intermixed, it is necessary to clarify which features should be represented on the map attached to the road ledger. If occupancy ledgers or permit documents are available, you can identify in advance what needs to be checked on site.

As reference information, check the coordinate system, control points, elevation datum, drawing scale, orientation, and route distance markers. Even when height information is not the primary purpose in 2D road ledger maps, control point information is indispensable for ensuring the consistency of surveying results. Overlaying different coordinate systems or older drawings without adjustment can cause positional shifts. It is important to ascertain each document's year of creation, surveying method, coordinate datum, and accuracy, and to decide in advance which information to prioritize.

Step 3 Obtain the necessary information through site inspection and surveying

After organizing the existing materials, on-site surveys and measurements are carried out. The quality of the road ledger attachment maps is largely determined by how accurately the necessary information can be obtained in the field. Existing materials alone cannot fully capture the current road geometry, the locations of structures, pavement edges, side ditches, boundary markers, encroachments, and the latest condition of road appurtenances. During the on-site survey, it is important to verify all information required for drawing preparation without omission.

The main information to collect in the field includes road centerlines, road edges, pavement edges, sidewalk–vehicle boundaries, gutters, curbs, retaining walls, slopes, bridges, culverts, drainage facilities, intersection geometry, driveway entrances, crosswalks, signs, lighting, guardrails, boundary stakes, boundary markers, manholes, and utility poles. How much to collect depends on the project specifications, but for features related to road management it is helpful to record on-site photos together with location information so they are easier to assess in later stages.

In surveying, it is necessary to ensure the accuracy of planimetric positions. Road ledger maps are expected to be drawings usable for management decisions, not rough sketches that are only visually discernible. Information related to road boundary lines and boundary points is handled with particular care. Because there are many cases where field boundary markers are tilted, buried, missing, or do not match the positions shown in the records, points found are not merely measured; they are recorded on the premise of verifying consistency with the documentation.

On-site photographs are also important. Because the attached map in the road ledger is a plan view, drawings alone cannot fully convey on-site conditions. The type of side ditch, the condition of the pavement edge, how boundary stakes appear, the state of slopes, and the installation status of encroachments are easier to verify later if photos are kept. Organizing each photo’s shooting location, shooting direction, and the name of the subject will be helpful for map editing and verification tasks.

When conducting field surveys, attention should be paid to balancing safety on the road with work efficiency. On roads with heavy traffic, the surveying work itself can be hazardous. Consider in advance the work area, time of day, traffic control, placement of personnel, and consideration for nearby residents and passersby. At intersections, narrow roads, blind curves, and roads without sidewalks, it is important to organize the survey items so that the necessary points can be obtained in a short time.

Also, during on-site surveys, it is effective to record not only the information that will be drawn on the plans but also information that will not be drawn, as material for decision-making. For example, ditches visible outside the road area, retaining walls on private land, old boundary markers, unused encroachments, and discrepancies between current conditions and reference documents—even if these are only minimally represented on the drawings—can help in determining the road area and management classification. Leaving notes about any oddities noticed on site will reduce rework when cross-checking documents later.

Step 4 Organize road areas and boundary information

One of the most important elements of two-dimensional road ledger maps is information on road areas and boundaries. Road ledger maps do not merely depict the shape of roads; they also serve to clearly indicate the extent that should be managed as road. Therefore, the task of organizing road area boundary lines, public–private boundaries, road centerlines, widths, and the history of area changes must be carried out with particular care.

When delineating road areas, overlay the existing road register, land acquisition documents, boundary determination documents, cadastral results, as-built drawings, and field survey results. These materials do not necessarily coincide perfectly. Older drawings may have low coordinate accuracy, causing on-site structures to appear displaced from boundary lines. Also, the register may not have been updated after road improvements, or the paved area on site may not accurately represent the road area.

What is important here is not to determine the road area based solely on its current appearance. The paved extent is not necessarily the road area; the road area may include side ditches and slopes. Conversely, parts that look like a road may be private driveways or undeveloped, unorganized land. In the road ledger and its attached maps, it is necessary to distinguish and organize legally and administratively defined road areas from the actual on-site road usage conditions.

For boundary points, correlate the survey results with the points shown in the records. If boundary stakes or boundary pins exist on site, measure their positions and verify whether they match the boundary points in the records. Organizing the point name, type, condition, and date of confirmation will help with later boundary verification and responses to inquiries. If boundary markers are unclear, treat them as unknown and take care not to draw speculative lines without justification as definitive.

Organizing road widths is also important. On the road ledger map, record the total width, carriageway width, sidewalk width, shoulder width, and other widths as needed. Widths are not necessarily constant; they vary at intersections, widened sections, narrow sections, bridge sections, and curves. When indicating where widths are recorded, choose an appropriate location as the representative cross section, and verify any discrepancies between field survey values and documentary values. It is important not only to record the numerical width but also to clearly specify from where to where the width was measured.

Road centerlines are involved in route management and length adjustments. The centerline may be treated either as a line that simply connects the center of the road shape or as a centerline established for route management purposes. At intersections and on curves, the way the centerline is defined can change lengths and positional relationships, so consistency with existing ledgers and route designation materials is checked. When the road boundary lines, centerline, and width annotations are consistent, the readability of the drawings is greatly improved.

Step 5 Create drawings of road structures and ancillary facilities

Once the road area and boundary information have been organized, the road structures and ancillary facilities are drafted. In the 2D road ledger map, features required for road management are placed clearly in plan view. The features covered span a wide range, including carriageways, sidewalks, shoulders, gutters, catch basins, curbs, retaining walls, slopes, bridges, culverts, guardrails, signs, lighting, street trees, lane markings, crossing facilities, traffic safety facilities, and encroachments.

When creating drawings, it is important to differentiate the representation for each type of feature. If road area lines, boundary lines, centerlines, structure lines, annotation lines, encroachments, and road appurtenances are drawn with the same line type or the same weight, the drawing becomes difficult to read. In maps attached to the road ledger, it is desirable that the road area and boundaries are distinguished first, and that the positions of road structures and facilities can then be confirmed. Distinguishing lines that are important for management from auxiliary lines makes the drawings easier to use in practice.

Side ditches and drainage facilities are features that are checked particularly frequently in road management. The location and type of side ditches, the presence or absence of covers, catch basins, cross culverts, and drainage direction all affect maintenance and rehabilitation planning. Two-dimensional drawings can sometimes make it difficult to fully represent drainage gradients and elevation relationships, but simply organizing plan locations and facility types can improve the efficiency of on-site inspections and repair assessments.

Retaining walls and slopes are also important when considering the road area and the scope of maintenance and management. In mountainous areas, on reclaimed land, or along rivers, slopes or retaining walls may exist outside the road edge. Whether these are included in the road manager’s responsibilities is determined by checking land documents and on-site conditions. On drawings, indicate the locations of the retaining wall top, retaining wall bottom, slope shoulder, slope toe, and so on as needed so that their relationship with the road boundary line is clear.

For road ancillary facilities, organize them with consideration not only for their location but also for their management significance. Signs, lighting, guardrails, reflective materials, visual guidance devices, wheel stops, and similar items relate to road users' safety. Recording them on the ledger-attached map makes it easier to consider inspection, updating, removal, and relocation. However, if every facility is drawn in excessive detail the drawings become cluttered, so determine the scope of depiction according to work specifications and management objectives.

Handling of encroachments is also important. Within the roadway there may be facilities managed by parties other than the road administrator, such as underground buried utilities, manholes, utility poles, conduits, and service connection equipment. How much to include in the 2D road ledger map depends on management policy and the availability of documentation, but being able to identify encroachments within the road area is useful for construction planning and encroachment coordination. It is important to separate their representation on drawings so that encroachments are not confused with the road’s structural elements.

Step 6 Organize drawing representations and attribute information

After drafting road structures and ancillary facilities on drawings, the drawing presentation and attribute information are organized. A two-dimensional road ledger map (2D) becomes difficult to use in practical work if it merely places lines and points. It is necessary to organize line types, text, annotations, layers, map frame, and legend so that one can read which lines are road area boundary lines, which points are boundary markers, and which facilities are subject to the road authority’s management.

In drawing representation, the most important thing is to make the meanings of lines consistent. Road area lines, public–private boundary lines, road centerlines, pavement edges, sidewalk–roadway boundaries, gutters, structure outlines, and encroachments should each be depicted so they are distinguishable. When updating previous drawings, it is also important to align with the existing representation rules. This is because if representations differ among multiple routes or between drawings from different years, users will hesitate each time they read the drawings.

Text annotations require a balance between readability and the amount of information. Place items such as route names, route numbers, start and end points, widths, lengths, structure names, facility names, boundary point numbers, intersecting road names, town names, directions, and scales as necessary. If there are too many annotations they will overlap lines and map features and make the drawing hard to read. Conversely, if there are too few annotations, the drawing’s meaning will be unclear when viewed on its own. Consider the intended use of the drawing and place the necessary annotations in appropriate positions.

Organizing layers is also important. In drawing data intended for editing, classifying layers into categories such as road area, boundaries, centerlines, road structures, ancillary facilities, encroachments, annotations, map frames, and background information makes later corrections and updates easier. Drawings with unorganized layers may look complete at first glance but make it difficult to select the features needed during updates and increase the likelihood of errors. Because maps attached to the road ledger are continually updated, it's especially important to design their structure from the outset with future updates in mind.

Consider how much attribute information to include. Even with 2D drawings, organizing information such as boundary point numbers, facility types, management classifications, installation year, document numbers, and confirmation dates makes it easier to link drawings with ledger information. Displaying all information as text on the drawing becomes cluttered, so it is more efficient to separate the information to be displayed from the information retained internally.

Map frames and legends are also important deliverables. Clearly indicate the drawing number, route name, creation date, author, scale, orientation, coordinate system, legend, area covered, and connections to adjacent sheets. When dividing into multiple sheets, organize overlaps and connection points of the map frames so it is clear which sheet represents which section. Ensuring that each sheet alone conveys the necessary information makes it easier to share within the office and to use for field verification.

Step 7 Perform reconciliation checks and organize deliverables

The final step is cross-checking and organizing the deliverables. The two-dimensional road ledger map is not complete simply when the drafting is finished. It is necessary to compare it with existing materials, field survey results, road ledger information, boundary documents, as-built drawings, and occupation documents, and to check for inconsistencies and omissions. By carrying out this verification process carefully, you will produce drawings that can be relied on in practice.

First, you should verify the road area boundary lines and boundary information. Check whether the road area boundary lines are consistent with existing documents, whether there are any significant discrepancies with on-site survey points, whether the boundary point numbers are correct, and whether any undetermined boundary locations are being represented as if they were confirmed. Errors related to the road area can affect occupancy permits, boundary negotiations, and construction design, so careful verification is necessary.

Next, verify roadway structures against the current conditions. Check whether items such as side gutters, pavement edges, sidewalks, retaining walls, slopes, bridges, catch basins, guardrails, signs, and lighting match the results of the field survey. Comparing site photographs with the drawings makes it easier to find omissions and positional errors. Pay particular attention to intersections, curved sections of the road, stretches with many driveways, and locations where the roadway width changes, as these areas are especially prone to oversights.

Checking the road width and length is also essential. Confirm that the width annotations on the drawings are consistent with survey measurements and ledger values, that the route length does not conflict with the road ledger records, and that the positions of the start and end points are correct. Width is basic information for road management and can affect traffic regulations, road improvements, and occupancy consultations. It is reassuring to be able to explain which documents or survey results the figures on the drawings are based on.

When organizing deliverables, separate and prepare editable data, view-only data, print-ready data, and verification/reference materials. Editable data should retain layers and attributes so it can be used for future updates. View-only data should be in a format that stakeholders can easily review. For print-ready data, confirm that drawing size, scale, text legibility, drawing frame, and legend are properly arranged. Organizing site photographs, survey results, document cross-check notes, and a list of unresolved issues will also make it easier to respond to inquiries later.

If there are unconfirmed items or matters for which judgment is pending, we will clearly indicate them in the deliverables. Maps attached to the road register do not necessarily allow every boundary or facility detail to be completely determined. If there are issues such as insufficient materials, unclear boundary markers, discrepancies with current conditions, or unverified occupancy information, we will organize them so they are identifiable on the drawings or on a separate sheet. Treating uncertain information as if it were confirmed can lead to problems later. It is important to document unknowns as unknowns and to adopt an approach that uses them to guide subsequent verification.

Common Mistakes and Preventive Measures in Creating 2D Road Ledger Attachment Maps

When creating 2D maps attached to the road ledger, there are several typical mistakes. The most frequent is failing to sufficiently review existing materials and producing drawings based solely on field surveys. The on-site road configuration is important, but the road area and management classification cannot be determined from current conditions alone. If the pavement edge or the position of a gutter is mistaken for the road boundary, the road area boundary line may become inaccurate. To prevent this, it is necessary to organize existing materials before conducting field surveys and to clarify the points that must be confirmed on site.

The next most frequent issue is insufficient information collected during the field survey. After measuring only the road edges and major structures and returning, you may find that boundary markers, encroachments, catch basins, pedestrian/vehicle boundaries, and points of width change are needed. Re-surveys take time and may require traffic control and on-site coordination. As a preventive measure, it is effective to organize the items to be checked before the survey and to align the understanding of the drawing preparer and the field surveyor.

A lack of standardization in drawing representations is also a major problem. If the same road area boundary line is drawn using different line types on different drawings, or if boundary lines and structure lines are difficult to distinguish, users may misread them. In particular, maps attached to the road register are used by multiple staff over long periods, so unifying representation rules is important. Decide line types, layers, annotations, and legends at the outset, and create drawings while checking consistency with existing drawings.

Care must also be taken with coordinate and positional shifts. If you overlay old drawings, scanned drawings, or materials with an unknown coordinate reference as-is, they may be misaligned with field survey results. Aligning lines without checking the cause of the discrepancy can produce drawings that look tidy but lack a valid basis. Confirm each source's reference system, creation date, and accuracy, and make clear which result will be used as the reference.

Furthermore, drawings that do not take ease of updating the deliverables into account are also problematic. Drawings that are only cosmetically refined can be difficult to modify later when adding facilities or changing zones. If layers are not organized, annotations are not separated, feature classification is ambiguous, or correspondence with source/reference materials is not maintained, confirmation will be required every time an update is made. Because maps attached to the road ledger are management documents used continuously, it is important to prioritize updatability from the time of creation.

Summary: To make road ledger maps useful, field accuracy and ease of updating are important

Creating 2D road ledger attached maps is not just the act of drafting drawings. It is a series of tasks: confirming the target area and objectives, gathering existing materials, obtaining necessary information through field surveys and measurements, organizing road zones and boundaries, depicting structures and ancillary facilities on the drawings, refining representations and attributes, and finally carrying out reconciliation and verification. None of these steps can be omitted, and insufficient organization in earlier stages leads to rework in later stages.

It is particularly important not to determine road limits or boundary information solely from current on-site conditions. Because the map attached to the road ledger is used as a basis for road management, it is necessary to comprehensively confirm existing documents, survey results, and field conditions. Pavement edges, side ditches, boundary markers, land acquisition documents, and road ledger records may not coincide, so you should adopt the practice of organizing the supporting evidence while preparing the drawings.

Also, even for two-dimensional drawings, accurate on-site location information is important. If the positions obtained in the field are ambiguous, the organization of road areas, facility locations, widths, and encroachments on the drawings will also be ambiguous. Considering future updates and on-site verification, linking and retaining survey results, photographs, notes, and attribute information is the key to creating a usable road ledger map.

In recent years, there has been a growing trend to obtain high-precision positions in the field and use them directly for checking and updating road ledger maps. Using smartphone-mounted GNSS high-precision positioning devices such as LRTK makes it possible to record with high accuracy field features such as boundary markers, road edges, gutters, manholes, signs, and structure locations, and to organize them easily together with photos and notes. When creating or updating 2D road ledger maps, if you want to streamline field verification, reduce effort in survey point management, and advance the process of reconciling drawings with actual conditions, considering the use of such high-precision positioning can make it easier to improve the overall accuracy and speed of road management operations.