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 faced serious challenges such as labor shortages and inefficiencies in field operations. As veteran engineers retire and fewer young workers enter the field, experienced personnel on-site are becoming scarce. In civil construction management, surveying and inspection tasks that were traditionally performed by two-person teams (one operating the instrument and one holding the staff, for example) are increasingly difficult to carry out with limited staff, placing greater burdens on each individual. Often a small team must handle multiple projects simultaneously, and relying on personalized, analog methods limits potential productivity gains.

Against this backdrop, expectations for industry-wide DX (digital transformation) are rising. Since around 2016, the Ministry of Land, Infrastructure, Transport and Tourism has promoted the *i-Construction* initiative, working to digitize and streamline the entire construction process from surveying and design to construction, inspection, and maintenance. The core of on-site civil DX is the ICT-ification of surveying and construction management tasks. For example, the adoption of 3D surveying technologies and automated construction machinery is accelerating efforts to achieve major labor savings while improving quality and accuracy. The government has set a target to "increase construction site productivity by 50% compared to conventional levels" and has supported the introduction of drone surveying, 3D laser scanners, and ICT-equipped construction machinery. However, high-performance surveying equipment is expensive and requires specialized skills, and drones are vulnerable to weather and flight restrictions—making immediate adoption difficult for small and medium-sized enterprises and many sites.

This has brought attention to new digital tools that anyone can use. Among them, "smartphone surveying," which combines smartphones with high-precision GPS receivers, is gaining traction as a groundbreaking on-site DX solution. With smartphone surveying, a palm-sized device can perform 3D measurement and stakeout, enabling tasks that once relied on seasoned professionals to be completed with simple operations. Intuitive smartphone apps familiar to younger generations can be learned in a short training period, allowing young workers to become effective quickly even under labor shortages. Additionally, the need to carry heavy equipment into hazardous heights or slopes is reduced, enabling non-contact measurement and improving safety. Among smartphone surveying technologies, LRTK, which this article introduces, is a key solution that can accelerate civil construction management DX.

Problems in Traditional Civil Construction Management

First, let’s summarize the issues present in traditional civil construction management that contribute to labor shortages and inefficiency.

• Surveying workload: Surveying typically required two or more people and advanced skills. Tasks such as operating total stations and setting out batter boards relied heavily on experienced technicians, and with fewer veterans available, many sites lack people who can perform surveys. When staff are limited, one person often must fulfill multiple roles, causing surveying to take longer and delaying overall construction progress. Equipment like tripods and prisms are heavy, making transport across mountainous or extensive sites physically demanding for workers.

• Paper ledgers and drawings for management: Project progress and survey results were mainly recorded by hand on paper ledgers and drawings, and data digitization lagged behind. For example, as-built measurements were often noted on paper in the field and later re-entered into spreadsheets in the office—leading to routine double entry and time-consuming post-processing. With data confined to physical folders, collected numerical data and photos frequently became buried. Locating needed information took time, and analyzing or sharing past records smoothly was difficult.

• Delayed information sharing and dependency on individuals: Field information was not transmitted to stakeholders in real time, causing communication lags. In traditional flows, survey results might be brought back to the office, compiled into reports, and only then submitted to supervisors or clients, sometimes taking days for review. During that interval the field could proceed and later be required to redo work based on feedback. Quality control often relied on veteran engineers’ experience and intuition, creating a high level of tacit knowledge and individual dependency, making it hard for newcomers to grasp the overall situation.

• Cumbersome as-built management and quality records: As-built management (confirming that post-construction structures match design dimensions and shapes) is crucial in civil works, but the conventional practice was to sample only a few measurement points and record them manually. For instance, roadbed height inspections often measured a few points along a long section with a level and judged pass/fail. This approach can miss overall variability or local defects. Records were organized in paper inspection sheets or photo albums, limiting the amount of evidence that could be preserved. Preparing quality records required time and manpower, and generating inspection documents placed a heavy burden on site supervisors.

Given these limitations, traditional methods restrict efficiency and data utilization, and under current labor shortages, operating job sites is becoming increasingly difficult. To resolve these issues and promote DX in civil construction management, it is essential to fundamentally rethink the entire workflow from surveying and measurement to recording and sharing. One promising approach is leveraging on-site digital tools such as the aforementioned smartphone surveying. In the next section, we’ll look at how LRTK, a representative of such new technologies, specifically addresses field problems and achieves both labor savings and datafication.

Core Tasks LRTK Solves and How It Drives On-site DX

LRTK (Lightweight RTK) is an innovative solution that turns smartphones into high-precision surveying instruments. 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 positioning and 3D measurement easily. RTK (Real-Time Kinematic) is a technology that corrects satellite positioning errors in real time, reducing typical GPS errors of several meters down to a few centimeters. LRTK leverages this RTK technology and supports Japan’s quasi-zenith satellite system "Michibiki" centimeter-class augmentation service (CLAS). This means it can continue high-precision positioning even in remote mountains or immediately after disasters where cellular service is unavailable, as long as satellite signals are accessible.

The ultra-compact, lightweight receiver simply mounts to a smartphone and connects via Bluetooth, eliminating the need to carry heavy tripods or fixed instruments—one person can complete surveying and recording with a smartphone in hand. Minimal specialized skills are required; users follow app prompts to digitize site topography and structures. Below are the main functions and benefits by which LRTK improves and enhances operations.

High-precision 3D scanning to datafy the site

Using LRTK, it becomes easy to digitize the entire site into 3D data. By leveraging a smartphone’s built-in LiDAR sensor and camera, structures and terrain can be scanned and recorded as point cloud data—collections of points. Because RTK provides accurate coordinates for the point cloud, measurement results can be matched to the design coordinate system. Tasks that previously required a multi-million-yen 3D laser scanner and a skilled operator are becoming possible for anyone using just a smartphone and LRTK.

For example, when checking the as-built condition of roads or development sites, conventional methods would measure a few cross-sections and create sectional drawings; with LRTK point cloud scans, one can obtain enormous point clouds simply by walking the site. After scanning, necessary cross-sections can be extracted in the app to measure dimensions, and automated earthwork volume (volume) calculations can be performed. Without bringing expensive dedicated equipment or a desktop computer to the site, measurement and analysis can be completed with just a smartphone and a small terminal—an innovative convenience.

The resulting 3D point cloud data serve as objective digital records of construction and terrain. Because entire surfaces can be digitized, variability and overlooked defects are reduced and quality control becomes more reliable. Visually, the whole site can be grasped intuitively, enabling sharing of conditions that photos or drawings alone could not fully convey. There are also major safety advantages: areas with steep slopes or collapse risk that are unsafe to approach can be scanned from a safe distance using a smartphone, enabling non-contact measurement. Compared to traditional risky surveying, this enhances worker safety and reduces risk. 3D scan results can be uploaded to the cloud and shared with the office, providing a foundation for data-driven as-built management DX.

Smart guidance for pile-driving and stakeout

LRTK is also powerful for layout tasks like pile-driving and stakeout that serve as construction references. The app can overlay pile positions or lines from design drawings onto the smartphone camera view using AR (augmented reality), so accurate stakeout can be performed without conventional surveying instruments. Tasks that used to rely on a veteran’s intuition about "about where to drive a pile" can be handled by loading drawing data into the app and simply pointing the smartphone to see a virtual pile projected on the ground. Even when the user walks around viewing from different angles, the AR display maintains perfect alignment with the real-world position, making it feel as if the pile is actually standing there.

This feature enables intuitive, high-precision alignment for pile-driving. Workers without surveying expertise can fine-tune positions by watching the phone screen, greatly reducing the labor involved in traditional batter board setup and stakeout. RTK-enabled smartphone AR overlays virtual models on the real world with accuracy down to a few centimeters, helping prevent misalignment or height differences that cause defects. Consequently, pile-driving timelines are shortened and quality improves, realizing sites where anyone can accurately install piles.

Improved efficiency in as-built verification

LRTK dramatically streamlines post-construction as-built verification and inspection work. Since the smartphone always displays centimeter-level current position, it’s easy to check differences from design values on-site immediately after construction or quickly measure prescribed inspection points. For instance, after concrete placement, LRTK can measure many surface points of a structure and display real-time deviations from design heights. If any deviations exceed tolerance, they can be identified instantly and the constructor can be asked to correct them on the spot.

Rather than sampling a few points as in traditional checks, wide-area surface measurements enhance coverage and reliability in as-built management. When point cloud data are available, necessary cross-sections can be 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 like losing track of which point a hand-written note referred to. Such data-based as-built verification enables faster inspections and reliable quality assurance.

Smoother consensus-building using AR

LRTK’s AR capability also transforms consensus-building and communication among stakeholders at construction sites. The app can overlay design lines or 3D completion models onto live site imagery on the smartphone screen, aligning digital information with the local context for direct verification.

For example, if complex pipelines are to be buried underground, projecting a virtual pipe model onto the ground via AR makes it easy to spot discrepancies between the design and the actual site at a glance. Overlaying the 3D design model onto a completed structure allows visual checks for finish deviations and early detection of defects. Inspections that relied on experienced craftsmen’s intuition become more intuitive for younger workers through AR-enabled visualization.

Easily understandable visual instructions are also useful in communications with clients and nearby residents. Showing a realistic on-site preview of the finished appearance—something that’s hard to imagine from paper drawings alone—smooths explanations and negotiations, reducing time and effort for consensus-building. LRTK’s AR functions are a powerful tool for visualizing the entire site, eliminating perception gaps and aligning stakeholders on the same image.

Use for time-series inspection and recordkeeping

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

For completed structures, measuring the same locations during periodic inspections with LRTK makes it easy to compare aging-related changes. In tunnel and bridge monitoring, overlaying past and current point clouds reveals differences, allowing quantitative checks for subsidence or deformation. Digital data can capture subtle changes that paper records could not, contributing to preventive maintenance and preservation.

Additionally, detailed construction-time data from LRTK serve as handover documentation for maintenance. For example, in buried pipeline works, performing a point cloud scan and 3D recording before backfilling lets future repairs or inspections precisely locate buried assets. Information that was previously accessible only from as-built 2D drawings becomes easier to reconcile with field conditions when measured 3D data are available, reducing excavation risk and facilitating swift repair planning. In this way, LRTK allows construction data to be accumulated as assets and provides a foundation for data utilization across construction and maintenance.

Enhancing Information Sharing and Quality Management via Cloud Integration

LRTK not only supports field measurement but also realizes DX for information sharing and recordkeeping through integration with cloud services. Time loss and workload caused by bringing field-collected information back for processing and reporting can be greatly reduced with cloud utilization. This section outlines the benefits of LRTK’s cloud-based data linkage.

Real-time sharing of field data and remote presence

Positioning data, point clouds, photos, and other data captured with LRTK can be uploaded to the cloud immediately from the smartphone. This allows geographically dispersed stakeholders—site and office personnel, contractors and clients—to synchronize and share the latest site conditions as digital data. For example, when a field worker uploads survey results to the cloud, supervisors or inspectors in the office can check the results in real time. If needed, they can immediately request additional measurements, and the field personnel can promptly conduct follow-up measurements or corrections. Such bidirectional, immediate coordination reduces rework and eliminates communication delays.

The Ministry of Land, Infrastructure, Transport and Tourism has recently promoted a new inspection approach called remote presence (remote on-site verification) that avoids traveling to the site by using data confirmation. Digitized site data from LRTK form the foundation for remote presence. With high-precision point clouds and geotagged photos shared via the cloud, clients can check as-built conditions from their office and point out required corrections to on-site staff during online meetings. Saving travel time and cost allows limited personnel to cover multiple sites concurrently—good news for municipal maintenance departments struggling with staffing. On-site operations where young staff perform measurements while veteran engineers supervise and instruct from the office become feasible with a cloud-sharing environment.

Automated processing of survey results and digital reports

Cloud-connected LRTK apps offer robust features for automated processing of survey results and report generation. The app can instantly compute required figures like distance, area, and volume from point cloud and coordinate data collected on site. This eliminates the need to return to the office to calculate earthwork volumes with CAD or perform manual area computations. For example, if point cloud data are uploaded to the cloud, volume calculations can be done automatically without specialized software, and results can be viewed through a web browser. Even users unfamiliar with specialized software can perform advanced analyses with one-click operations, lowering the barrier between fieldwork and data processing.

Furthermore, LRTK can output digital reports 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 once required affixing photos to sheets and writing explanations can now be auto-generated and submitted on-site. Cloud-stored data are easy to share with internal teams and subcontractors, and information transfer speeds are dramatically higher than in the era of paper handoffs and faxes. Paperless workflows and automated reporting reduce the time site supervisors spend on paperwork, enabling them to focus more on construction and safety management.

Advanced quality control and maintenance use of data

Digitizing on-site as-built and measurement data with LRTK directly advances quality control. As 3D as-built data and geotagged photos accumulate in the cloud, inspectors can objectively evaluate quality from both numerical and visual perspectives. Strict comparisons with design drawings can be performed quickly, greatly reducing the risk of overlooking errors or defects. As data are saved with timestamps, it becomes clear "when, where, and how" work was performed, contributing to quality traceability.

Digital information accumulated during construction is also an extremely valuable resource for the post-handover maintenance phase. Three-dimensional, quantitative information that paper deliverables could not provide—such as point clouds and coordinate data—can be leveraged for future repairs and inspections. For example, in replacement works for buried road utilities, referencing the construction-time 3D record allows excavation with accurate knowledge of what is buried at which depth. This reduces unnecessary digging and accidents, ultimately lowering costs and shortening schedules.

Veteran maintenance staff may be able to guide younger personnel online using construction-time data without being physically present at the site. The data-linked construction management enabled by LRTK brings substantial value by improving efficiency across the entire infrastructure lifecycle.

Conclusion

DX adoption is now an unavoidable and critical theme for civil construction management facing labor shortages and operational efficiency challenges. In this context, LRTK, which can be started easily with a smartphone and a small device, is an ideal solution for taking the first step into on-site DX. Tasks that previously required a team—surveying, inspection, and recording—can be completed by one person with a single smartphone when LRTK is introduced. Real-time access to high-precision positioning and 3D data creates a seamless workflow of "measure, check, record," dramatically reducing wasted waiting time and rework. Cloud sharing lowers the barriers between field and office and enables flexible workstyles such as remotely managing multiple sites simultaneously.

Compared with dedicated equipment, LRTK has a lower cost and learning curve, making it attractive for small and medium-sized firms and local governments. Because only a smartphone and a small receiver are required, heavy equipment purchases and large-scale training are unnecessary, allowing a small-scale start that reflects actual site conditions. LRTK adoption has already begun across civil and infrastructure management sites nationwide, and its accuracy and functions conform to the Ministry’s draft guidelines for 3D as-built management, making it suitable even for public works.

DX in civil construction management driven by cutting-edge digital technology is no longer a future concept but an ongoing trend. Utilizing LRTK as the trump card, processes from surveying to as-built management, reporting, and sharing can proceed remarkably smarter. Why not start DX on your site with this simplified surveying? LRTK, which changes conventional on-site practices, will surely become a powerful ally in improving productivity and operational efficiency.