Tackling Severe On-site Labor Shortages with LRTK! Labor-saving Measures for Civil Construction Management Engineers

On-site labor shortages intensify – impact on civil construction management engineers

In recent years, the construction and civil engineering industries have faced a chronic problem of workforce shortages and an aging pool of skilled workers. Particularly for civil construction management engineers who oversee sites, the difficulty of securing personnel is a challenge that directly affects daily operations. In fact, according to a survey by Teikoku Databank, about 24% of construction industry workers are 60 years or older, and nearly half are 50 or older [帝国データバンクの調査](https://www.tdb.co.jp/report/economic/20250109-laborshortage-br2024/). With the number of young entrants stagnating and veteran technicians retiring in succession, it has become urgent to devise ways to run sites with a limited number of people.

In this situation, companies are seeking ways to cope by reducing labor and improving efficiency. The Ministry of Land, Infrastructure, Transport and Tourism’s [I-Construction](https://www.mlit.go.jp/tec/i-construction/index.html) initiative emphasizes achieving increased productivity by using ICT technologies to enable “efficient construction with fewer people and in less time.” As on-site DX (digital transformation) accelerates, the possibility of single-person operations for basic tasks such as surveying and layout marking is beginning to attract attention.

The new norm of “one-person surveying” – labor-saving surveying with the latest technologies

Traditionally, surveying work has been done by a team of 2–3 people. Typically, one person operates a total station (survey instrument) while another stands at the target point tens of meters away holding a staff or prism, requiring coordinated teamwork. This method requires a great deal of time and effort from setup to teardown, and surveying a large site could easily take a full day. Because these analog tasks rely on manual labor, there is also the risk of human error; misreads or recording mistakes that necessitate re-measurement can cause schedule delays and cost increases.

However, with the advent of the latest technologies, the concept of “one-person surveying” is becoming realistic. As the name implies, this approach aims to complete surveying with a single person, and it has attracted attention amid severe labor and surveyor shortages. The key technologies are high-precision satellite positioning (GNSS) and the use of digital devices. Conventional GPS used to have meter-level errors and was inadequate for construction surveying, but the spread of RTK-GNSS (real-time kinematic positioning) now makes centimeter-level positioning available in real time. Moreover, the fact that this high-precision GNSS can now be used on convenient devices such as smartphones has overturned the conventional wisdom about one-person surveying.

For example, surveying that previously took two people half a day can, in some cases, be completed by a single person in a short time simply by attaching an RTK-capable compact GNSS receiver to a smartphone. Even less experienced junior staff can obtain high-precision measurements by following the guidance displayed on a smartphone app. Government-led DX promotion has also helped, and the long-held belief that “surveying must be done by a team” is beginning to change. On the ground, voices saying, “If one person can measure accurately, that’s more efficient,” are starting to emerge, and one-person surveying is becoming the new normal in an era of labor shortages.

Challenging “one-person layout marking” – completing layout work solo

Not only surveying but also labor-saving for layout marking (marking pile-driving locations) is a major challenge on sites. Setting out building or structure positions and baseline lines has typically been a complex task performed by multiple people. For example, one person operates measuring instruments while another marks positions with a marking pot or chalk on site—an labor- and time-intensive process. Especially where the ground is hard or access is poor, driving stakes itself can be difficult and position identification challenging.

Enter one-person layout marking, which combines survey data with AR (augmented reality) technology. Specifically, coordinate data for reference points and structure locations included in design drawings are imported to a smartphone via the cloud; when viewed through the camera of a smartphone or tablet on site, virtual stake markers and lines are displayed on the screen as AR overlays. The worker can then simply mark the site guided by the positions shown on the screen, enabling one person to accurately mark stake-driving locations. Even on steep slopes or rocky ground, position setting can be performed without assistants, contributing to improved safety.

With such AR stake-driving, layout marking work that formerly required a surveying team making round trips can be performed continuously by a single person. Because the next installation position is displayed sequentially on the smartphone screen, the worker moves and marks points in tempo following the instructions. As a result, large-area layout work can be completed in a short time, and the required personnel can be drastically reduced. It also enables flexibility: a site manager’s request like “I want to drive a stake here” can be immediately converted to coordinates and displayed in AR, allowing stakeholders to share the image on the spot. One-person surveying × AR thus enables both significant labor reduction and improved accuracy in surveying and layout marking processes.

Efficiency enabled by RTK-GNSS and smartphone use

The core technologies supporting the one-person surveying and one-person layout marking described above are high-precision GNSS (RTK) and smartphone utilization. In the RTK method, the rover (the surveyor’s GNSS receiver) and the base station (reference station) exchange data in real time to correct common errors, dramatically improving positioning accuracy. As a result, both horizontal and vertical positioning can be achieved within a few centimeters of error, reaching accuracy comparable to conventional optical surveying instruments. This technological innovation is creating an environment where “the machine can measure accurately even without a veteran surveyor.”

Moreover, solutions that allow this RTK-GNSS to be connected to smartphones or tablets have further accelerated on-site efficiency. Because recording survey points, taking photos, and inputting notes can be done intuitively on a phone screen, anyone can easily acquire survey data through an easy-to-use UI. There is no need to carry heavy tripods or specialized equipment; the revolutionary ease of completing surveying while walking the site with a pocket-sized device and a single smartphone has arrived. This enables agile operations such as quickly measuring current site conditions during spare time on small sites or teams with limited personnel and immediately sharing the results.

Smartphone-built sensors and functions also contribute to efficiency. For example, a LiDAR-equipped smartphone can walk a site while 3D-scanning the surrounding terrain and structures to generate point cloud data, allowing detailed as-built understanding and earthwork volume calculations on the spot. Photos taken with the camera are automatically tagged with accurate position coordinates and orientation and saved to the cloud, making it immediately clear “which location and direction the photo was taken from.” This fusion of smartphone × surveying technology is a highly effective entry point for site DX and creates a flow of data utilization from surveying through construction management and inspection.

On-site DX accelerated by cloud and data sharing

To fully leverage the benefits of one-person surveying and one-person layout marking, integration with cloud services is indispensable. Traditionally, survey results obtained on site were recorded in notebooks or on paper drawings and brought back to the office for digitization and drawing updates, which introduced delays between measurement and information sharing and slowed decision-making.

Modern smartphone surveying solutions now automatically upload measured data to the cloud on the spot, enabling immediate sharing. For example, some systems plot point coordinates, photos, and notes in real time on a cloud-based map, allowing colleagues in the office or clients to check the situation instantly. By simply sharing a dedicated URL, stakeholders can view the latest data without logging in, enabling speedy online progress reporting and as-built inspections. Because data organization and transmission are completed the moment measurements are taken on site, the traditional lag of “measuring and reporting taking several days” is dramatically shortened.

Furthermore, high-precision site data accumulated in the cloud can be used in subsequent construction planning and maintenance. Survey data can be immediately imported into construction management software or CAD drawings for as-built management, and accumulated data can be compared over time for long-term monitoring of ground subsidence, among other applications. With individuals easily collecting and sharing data, information flow across the site speeds up, decision-making becomes faster, and errors and oversights are reduced. Cloud utilization is thus a key factor in improving team-wide productivity in an era of labor shortages.

Small-site introduction scenarios – concrete examples of labor reduction

On small construction sites suffering from labor shortages, the one-person surveying technologies described above can serve as ready-to-use assets. Consider a civil engineering site with just a few employees. Previously, surveying reference points and checking elevations might have been outsourced to a surveying company each time or handled by a qualified employee who would spend half a day on the task while juggling schedules. However, by introducing one-person surveying tools, civil construction management engineers themselves can quickly measure the site during spare time and immediately share the data via the cloud.

For example, a site-wide measurement before the morning meeting can review the previous day’s progress with 3D data, or a new staff member can measure trench depths at multiple locations alone and submit the data immediately. Because you can measure the necessary locations when needed without tying up multiple people, these tasks can be performed in parallel with other work, improving overall site efficiency. In addition to cutting outsourcing costs, building your own data repository supports in-house accumulation of know-how.

Another concrete example is layout marking on a narrow road construction site. Where setting curb locations used to require a pair of workers, AR-enabled one-person layout marking allows the supervisor to complete the task alone. Upload the drawing data coordinates to the cloud and mark while checking the smartphone screen on site, and the layout can be finished accurately in a short time. Other staff can concentrate on different tasks, enabling efficient work sequencing even with a small crew. The smaller the site, the greater the effect of one-person operations. Breaking the old constraint of “we’ll postpone surveying or layout marking because of labor shortages,” the ability to perform tasks immediately when needed directly contributes to productivity improvements and a more flexible response on site.

Simple surveying with LRTK – features and benefits of adoption

One example of a solution that supports the one-person surveying and one-person layout marking approaches described above is LRTK. LRTK is a smartphone-mountable ultra-compact RTK-GNSS device developed by a startup spun out of the Tokyo Institute of Technology; when attached to a smartphone or tablet, it transforms the device into a centimeter-accurate surveying instrument. Below are the main features of simple surveying enabled by LRTK.

• Ease of use (pocket-sized device for immediate surveying): The LRTK unit is small and lightweight, weighing about 160 g and about 1 cm thick (0.4 in). It is attached to the back of a smartphone using a dedicated attachment and connects via Bluetooth or similar methods for immediate use. Whereas surveying used to require carrying several kilograms of equipment and setting up tripods, with LRTK a single smartphone enables one-person surveying through stake-driving, completing tasks end-to-end. Its portability makes it easy to carry to the site and measure whenever and wherever needed.

• Centimeter-level high-precision positioning: By supporting the RTK method, LRTK achieves high accuracy with horizontal accuracy of approximately ±2～3 cm (±0.8～1.2 in) and vertical accuracy of ±3～4 cm (±1.2～1.6 in). Smartphone-only GPS typically has meter-level errors, but the use of a dedicated antenna and correction data reduces errors to just a few centimeters. It also supports correction signals (CLAS) provided via the electronic reference point network (Ntrip) and Japan’s quasi-zenith satellite “Michibiki,” enabling high-precision positioning from satellites even in remote mountainous areas without communication coverage. This ensures practical accuracy for everything from typical boundary surveying to as-built management.

• Cloud integration and real-time sharing: Data collected with the LRTK dedicated app is immediately uploaded to the LRTK Cloud. Point coordinates, photos, and notes are displayed on a cloud-based map and can be viewed or downloaded in real time from office PCs. Measurement results can be exported in CSV or drawing data formats, facilitating report creation and CAD integration. By issuing shareable links from the cloud, you can share the latest data with external stakeholders with a single click. This greatly reduces the time required for post-survey data processing and supports site visualization and rapid decision-making.

• Rich features (point cloud measurement, AR display, etc.): LRTK offers more than simple point measurements; it is equipped with features that support site DX. Combined with a smartphone’s LiDAR, it can perform high-density point cloud scanning, enabling rapid 3D modeling of terrain and structures. Photos taken are automatically tagged with positioning information and linked to the cloud map for management. In addition, AR functions overlay acquired survey data and design models on the camera view, allowing on-site visualization of design points and completed models in the real world. This enables intuitive construction management by a single person, such as guided displays for stake-driving positions and sharing completed-image views.

• High portability and safety: The compact, battery-powered LRTK can perform about 6 hours of continuous surveying and can be extended with a mobile battery. Because it can be carried in one hand even on poor footing, it contributes to improved safety for the surveyor. Reducing the number of personnel and minimizing entry into hazardous areas also provides clear safety benefits.

• Cost performance: Conventional high-precision surveying equipment could cost several million yen, but LRTK’s simple device design helps keep introduction costs down. Its very reasonable price range makes it realistic to equip one device per person. If multiple staff members each carry an LRTK to perform surveying and recording, it directly leads to improved productivity across the site.

In this way, LRTK is an innovative tool that allows anyone, anywhere, immediately to perform centimeter-accurate surveying and layout marking. For civil construction management engineers struggling with labor shortages, it can be a powerful ally that balances on-site DX and labor reduction.

Conclusion: DX and one-person surveying are keys to surviving the labor shortage era

In construction sites facing severe labor shortages, labor reduction through digital technology is an unavoidable theme. Civil construction management engineers in particular are expected to deliver results with limited resources while maintaining site-wide efficiency and quality. In response to such challenges, practicing the one-person surveying and one-person layout marking approaches introduced here and adopting smartphone GNSS solutions like LRTK are promising breakthroughs.

With cutting-edge positioning technology and cloud utilization, the range of what “one person can do” is steadily expanding. Now, as the norms of surveying and layout marking change, it is an opportune time to take the first step toward on-site DX. Embrace technologies that deliver the twin benefits of reduced labor and improved measurement precision, and overcome the storm of labor shortages.