Accelerating Civil Construction Management DX with LRTK: Achieving Labor Savings and Datafication at Once

Current State of Civil Construction Management: Labor Shortages, Inefficiency, and the Need for DX

In recent years, the construction and civil engineering industries have been facing serious challenges of labor shortages and on-site inefficiencies. Retirements of veteran engineers due to aging and a decline in young entrants have led to a shortage of experienced personnel at worksites. In civil construction management, tasks such as surveying and inspections that traditionally required two-person crews (one operator and one rod person, for example) are becoming difficult to carry out with limited staff, increasing the burden on each individual. At the same time, many personnel must manage multiple projects simultaneously, and relying on personalized, analog methods limits potential productivity improvements.

In response to these issues, expectations for DX (digital transformation) across the industry are rising. Since around 2016, the Ministry of Land, Infrastructure, Transport and Tourism has been promoting *i-Construction*, working to digitize and streamline the entire construction process from surveying and design to construction, inspection, and maintenance. At the core of on-site civil DX is the ICT-ization of surveying and construction management tasks. For example, the introduction of 3D surveying technologies and automated construction machinery is actively pursued to achieve major labor savings while improving quality and accuracy. The government has set a target to “improve construction site productivity by 50% compared to conventional methods,” and has supported the adoption of drone surveying, 3D laser scanners, and ICT construction machinery. However, high-performance surveying equipment is expensive and requires specialized skills, and drones are affected by weather and flight restrictions, making immediate on-site adoption by small and medium-sized enterprises challenging.

This has drawn attention to new digital tools that anyone can use. Among them, “smartphone surveying,” which combines smartphones with high-precision GPS receivers, is emerging as a groundbreaking solution for on-site DX. With smartphone surveying, a palm-sized device can perform 3D measurements and stakeout, enabling tasks formerly dependent on experienced personnel to be completed with simple operations. Intuitive smartphone apps that younger generations are familiar with can be learned in a short training period, making it easier for young staff to become immediately effective even amid labor shortages. It also reduces the need to carry heavy equipment into dangerous heights or slopes; non-contact measurement improves safety. Among smartphone surveying technologies, the LRTK introduced in this article is a key solution to accelerate civil construction management DX.

Challenges in Conventional Civil Construction Management

First, let’s organize the problems present on conventional civil construction sites. The following issues are cited as factors causing labor shortages and inefficiency.

• Burden of surveying tasks: Surveying has typically required two or more people and highly advanced skills. Operations like total station handling and setting batter boards often depended heavily on experienced technicians, and with fewer veterans, many sites lack people who “can do surveying.” When personnel are limited, one person must play multiple roles, causing surveying to take longer and stalling overall construction progress. Equipment also includes many heavy items such as tripods and prisms, and carrying them across mountainous or expansive sites imposes physical strain on workers.

• Management with paper logs and drawings: Recording construction progress and surveying results has centered on handwritten records in paper logs and drawings, and data digitalization has been limited. For example, measurement results would be scribbled on paper on-site and then re-entered into spreadsheet software in the office, resulting in routine double entry and post-site organizing work. Because information remained in on-site folders in paper form, collected numerical data and photos tended to be buried. Finding needed information took time, and analyses or sharing that made use of past records could not be done smoothly.

• Delayed information sharing and dependence on individuals: Information obtained on-site was not conveyed to stakeholders in real time, causing communication lags. For example, under a conventional flow where surveyed results are taken back to the office, compiled into a report, and then submitted to superiors or clients, confirmation could take days. Meanwhile the site could progress and later receive “redo” instructions, causing rework. Quality was often managed based on the experience and intuition of veteran technicians; tacit knowledge led to individual dependence, making it difficult for newcomers to grasp the overall situation.

• Complexity of as-built management and quality records: As-built management—confirming that constructed elements meet the design dimensions and shapes—is important in civil works, but traditionally only a few measurement points were manually selected and recorded. For example, to inspect the subgrade height of a road, several locations might be measured with a level and judged. This method can miss overall variability and local defects. Records were organized by pasting into paper inspection sheets or photo albums, limiting the amount of evidence that could be retained. Creating quality records required time and personnel, and preparing inspection documents placed a heavy burden on site supervisors.

As shown above, conventional methods limit efficiency and data utilization, and under current labor shortages it becomes increasingly difficult to run worksites. To solve these problems and promote DX in civil construction management, it is necessary to fundamentally rethink the entire flow from surveying and measurement to recording and sharing. One promising approach is the use of on-site digital tools such as smartphone surveying. The next chapter looks at how LRTK, a representative of these new technologies, specifically addresses site issues and achieves labor savings and datafication.

Key Tasks LRTK Solves and Promoting On-site DX

LRTK is a groundbreaking solution that transforms a smartphone into a high-precision surveying instrument. It consists of a small RTK-GNSS receiver (positioning terminal) that attaches to a smartphone and a dedicated app, enabling anyone to perform centimeter-level (half-inch-level) positioning and 3D measurement easily. RTK (Real Time Kinematic) is a technique that corrects satellite positioning errors in real time, reducing GPS errors that are usually several meters to a few centimeters. LRTK leverages this RTK technology and supports Japan’s quasi-zenith satellite system “Michibiki” centimeter-class augmentation service (CLAS). Therefore, even in remote mountains or immediately after disasters where cellular service is down, as long as satellite signals can be received from overhead, high-precision positioning can continue.

With an ultra-compact, lightweight receiver attached to a smartphone and connected via Bluetooth or similar, setup is complete. There is no need to carry heavy tripods or fixed equipment; one person can complete surveying and recording with a smartphone in hand. Little specialized skill is required; by following the app’s on-screen instructions, users can digitize site terrain and structures. Now, let’s examine the specific tasks that LRTK can make more efficient and advanced, reviewing main functions and effects.

Datafication of the Site with High-Precision 3D Scans

Using LRTK, it becomes easy to digitize the entire site into 3D data. By utilizing a smartphone’s built-in LiDAR sensor or camera, structures and terrain can be scanned and recorded as point cloud data, which is a collection of points. RTK assigns accurate coordinates to the acquired point clouds, allowing measurement results to be referenced against the design coordinate system. Tasks that once required million-yen-class 3D laser scanners and skilled operators are increasingly possible with just a smartphone and LRTK.

For example, when confirming the as-built condition of roads or development sites, instead of measuring several cross-sections point-by-point to create sectional drawings, an LRTK point cloud scan can collect an enormous number of points simply by walking through the site. After scanning, the app can immediately slice the required cross-sections and measure dimensions, and automatically perform earthwork (volume) calculations for fills and excavations. The convenience of completing measurement through analysis with only a smartphone and a small terminal—without bringing expensive dedicated equipment or a PC to the site—is revolutionary.

The 3D point cloud data obtained can be preserved as objective digital records of construction as-built and terrain. Because whole surfaces can be digitized, variability and overlooked defects are reduced, increasing the reliability of quality control. The visual, intuitive grasp of the whole site allows sharing of conditions that photos or drawings alone could not convey. There are also major safety benefits: for steep slopes or areas at risk of collapse where people cannot approach safely, scanning from a safe distance by holding up a smartphone allows assessment of the situation. Compared to the traditional risky approach of close-up surveying, non-contact measurement helps secure worker safety and reduce risk. Scan results can be uploaded to the cloud and shared with the office, forming the basis for data-driven as-built management DX.

Smart Guidance for Piling and Layout

LRTK is also powerful for pile driving and layout tasks that set construction references. The app can display pile positions and lines from the design on the smartphone camera view using AR (augmented reality), enabling accurate stakeout without traditional surveying instruments. Tasks once guided by veteran intuition—like “drive piles around here”—can be performed by loading drawing data into the LRTK app and simply pointing a smartphone to see the expected piles as virtual objects placed on the ground. Even when viewed from different angles, the AR pile display remains fixed in the correct position, giving the impression that the piles are actually standing.

This function allows intuitive and high-precision pile alignment. Workers without surveying expertise can fine-tune positions while looking at the smartphone screen, greatly reducing the effort required for batter board setup and layout work. RTK-enabled smartphone AR overlays virtual models onto the real world with accuracy that does not allow for several centimeters of error, helping prevent mistakes such as pile misplacement or height discrepancies. As a result, pile-driving stages see time savings and quality improvements, enabling a site where anyone can drive piles accurately.

Improved Efficiency in As-Built Verification

Post-construction as-built verification and inspection tasks are also dramatically streamlined with LRTK. Because the smartphone always displays current position with centimeter-level accuracy (half-inch accuracy), it is easy to check differences from design values on the spot or quickly measure designated inspection points immediately after construction. For example, after concrete placement, LRTK can be used to measure numerous points on the surface of a structure and check in real time for deviations from design heights. If errors exceed tolerance at any location, they can be immediately identified and correction can be requested on the spot.

Rather than spot checks at sampled points as in the past, LRTK enables planar measurement over wide areas, enhancing coverage and reliability of as-built management. When point cloud data is available, required cross-sections can be freely extracted later for dimensional checks, reducing the need to return to the site for re-inspection. LRTK automatically saves and records all measured data, preventing human errors where notes on paper later become ambiguous as to which point they referred to. This data-driven as-built verification enables quicker inspections and reliable quality assurance.

Smooth Consensus Building Using AR

LRTK’s AR capabilities also innovate consensus building and stakeholder communication on site. By overlaying design lines and 3D models of the expected finished appearance onto live site imagery on a smartphone screen, digital information can be matched to on-site conditions for confirmation. This makes it possible to visually share the final image on site that is hard to convey with paper drawings alone.

For example, even when complex piping routes are buried underground, projecting virtual pipe models onto the ground using smartphone AR instantly reveals discrepancies between the design and the site. Overlaying a 3D model of the design onto the constructed element allows visual checking of finishing errors and early detection of defects. Inspections that relied on the intuition of experienced craftsmen can be made more accessible to younger staff through AR visualization, enabling intuitive pass/fail judgments.

Clear visual instructions that anyone can understand are also helpful in communications with clients or nearby residents. Showing the expected finished appearance on site makes explanations and consultations smoother, reducing the time and effort required for consensus building. LRTK’s AR function is a powerful tool that visualizes the entire site to eliminate perception gaps and ensure all stakeholders share the same image.

Use for Time-Series Inspections and Records

High-precision data obtained with LRTK can be utilized not only during construction but also for time-series inspection and maintenance. Scanning the site at each stage of work allows tracking progress and changes in 3D over time. For example, daily point cloud records of changing terrain during excavation make it possible to accurately determine how much excavation progressed at any given time. This is useful not only for process management but also as supporting documentation for progress-based payments and settlement of additional work.

For completed structures, taking measurements with LRTK at the same locations during periodic inspections makes comparison of long-term changes easy. For tunnel and bridge monitoring, overlaying past and recent point cloud data to check differences allows quantitative confirmation of any settlement or deformation. Digital data can capture subtle changes that were difficult to detect with paper records, contributing to preventive maintenance.

Moreover, detailed construction-time data acquired by LRTK becomes handover material for the maintenance phase. For example, in buried pipe works, scanning and creating a 3D record of pipe positions before backfilling enables accurate knowledge of “what is buried where” during future repairs or inspections. While conventional as-built documents only showed planar drawings, 3D data based on actual measurements makes it easier to match records to the physical site, reducing excavation risks and enabling quicker repair planning. In this way, LRTK accumulates construction data as assets and provides a foundation for consistent data use from construction to maintenance.

Advanced Information Sharing and Quality Control via Cloud Utilization

LRTK not only supports field measurement but, when integrated with cloud services, also realizes DX for information sharing and recordkeeping. Time losses and labor associated with bringing on-site information back to the office for organization and reporting are drastically reduced through cloud utilization. This chapter introduces the benefits of LRTK’s cloud data linkage.

Real-Time Sharing of On-Site Data and Remote Presence

Positioning data, point clouds, photos, and other items collected by LRTK can be uploaded to the cloud from the smartphone immediately. This allows geographically dispersed stakeholders—field and office, contractors and clients—to synchronize and share the latest site status as digital data. For example, when a field staff uploads surveying results to the cloud, supervisors and inspectors in the office can check those results in real time. If necessary, they can instantly instruct the field to take additional measurements, and the person on site can promptly perform follow-up or corrections. This bidirectional immediate coordination reduces rework and eliminates communication losses.

The Ministry of Land, Infrastructure, Transport and Tourism has recently been actively promoting remote presence as a new inspection method that avoids site visits by verifying data remotely. Digitized site data from LRTK provides the foundation for remote presence. If high-precision point clouds and geotagged photos are shared via the cloud, clients can check as-built conditions from the office and point out corrective items while communicating with on-site staff in online meetings. Reduced travel time and cost allow a limited number of people to cover multiple sites concurrently, which is welcome news for municipalities struggling with labor shortages in maintenance departments. With a cloud-sharing environment, young staff can perform measurements on-site while veteran engineers review and instruct from the office, making efficient operations increasingly feasible.

Automatic Processing of Survey Results and Digital Forms

LRTK apps linked to the cloud also provide robust automatic processing of survey results and form generation. From point cloud and coordinate data collected on-site, the app instantly computes and displays required values such as distance, area, and volume. This saves the effort of returning to the office to calculate earthwork quantities in CAD or performing manual area computations. For example, by uploading point cloud data to the cloud, excavation volume calculations are automated and can be viewed via a web browser without specialized software. Even those unfamiliar with specialist software can perform advanced analyses with the push of a button, greatly lowering the barriers between field work and data processing.

Furthermore, LRTK can output digital forms with a single tap. If photos and notes are linked to measured points in the app, they can be compiled into a PDF report instantly. Survey reports that previously required tedious tasks—pasting photos onto templates and handwriting explanations—can be auto-generated on-site and submitted immediately. Cloud-stored data is easy to share within the company and with subcontractors, and information transmission speed is dramatically improved compared to paper handoffs or faxing. Paperless operations and automated form generation reduce the time site supervisors spend on documentation, allowing them to focus more on core construction and safety management.

Advanced Quality Control and Data Use for Maintenance

Turning site as-built and measurement results into a comprehensive database via LRTK directly elevates quality control. As 3D as-built data and geotagged photos accumulate in the cloud, inspectors can objectively evaluate quality using both numerical and visual information. Strict comparisons with design drawings can be completed quickly, greatly reducing the risk of overlooking defects. Because data is stored with timestamps, it becomes traceable later—clarifying when, where, and how construction was performed—and contributes to quality traceability.

Additionally, the digital information accumulated during construction becomes a valuable resource in the post-handover maintenance phase. Three-dimensional, quantitative information that paper drawings and photos alone could not provide is preserved as point clouds and coordinate data, proving useful in future repairs and inspections. For example, during replacement work of buried road utilities, referring to construction-time 3D records allows excavation to proceed with accurate knowledge of what lies at what depth. This reduces unnecessary digging and prevents accidents, ultimately lowering costs and shortening schedules.

Veteran maintenance staff can also support younger personnel online by reviewing construction-time data without visiting the site. Data-linked construction management enabled by LRTK thus contributes to efficiency throughout the infrastructure life cycle.

Conclusion

In civil construction management sites facing labor shortages and efficiency challenges, DX is now an unavoidable and important theme. In this context, LRTK—easy to start with a smartphone and a small device—is an ideal solution for taking the first step toward on-site DX. Tasks that once required a team—surveying, inspection, and recordkeeping—can be completed by one person with a single smartphone when LRTK is introduced. Real-time utilization of high-precision positioning and 3D data seamlessly connects the processes of measuring, verifying, and recording, dramatically reducing wasted waiting times and redo work. Cloud sharing lowers the barrier between site and office, enabling flexible operations such as remotely managing multiple sites simultaneously.

Compared to dedicated equipment, LRTK has lower introduction costs and learning hurdles, making it attractive for small and medium-sized enterprises and local governments. With only a smartphone and a small receiver, costly machinery purchases and large-scale training are unnecessary, allowing DX to proceed with a small-start approach that fits actual site conditions. LRTK is already being adopted at civil and infrastructure management sites nationwide, and because it offers accuracy and functions compatible with the MLIT’s 3D as-built management guidelines (draft), it can be used with confidence for public works.

DX in civil construction management using the latest digital technologies is no longer a future concept but a current trend. By leveraging LRTK as the trump card, processes from surveying to as-built management, reporting, and sharing will proceed far more smoothly. Why not start DX at your site with this simple surveying? LRTK, which changes the conventional wisdom of worksites, is sure to be a powerful ally in improving productivity and operational efficiency.