2025 Edition: Latest Trends in i-Construction — Site DX Transformed by Smartphone Surveying

Since the Ministry of Land, Infrastructure, Transport and Tourism proposed "i-Construction" in 2016, the construction industry has been actively pursuing productivity improvements and digitalization at job sites. In 2024, overtime work regulations for the construction industry (the so-called "2024 problem") began to be enforced, marking a turning point in workstyles and workforce retention. As of 2025, construction site DX (digital transformation) is an urgent necessity to respond to these circumstances.

Among the developments attracting attention is high-precision "smartphone surveying." Surveying work that traditionally required specialized equipment and multiple personnel is becoming feasible as single-person surveying through smartphones equipped with RTK (real-time kinematic) technology. This method, which allows easy acquisition of positional and terrain data on site and immediate cloud sharing, is quietly spreading as a trump card for site DX. This article explains, based on i-Construction policies and the current situation as of 2025, the background driving the need for digitization starting from surveying, the role and adoption status of single-person surveying using smartphone RTK, the prospects for consistent data utilization from surveying through construction, inspection, and maintenance, and the changing human resource profiles and on-site skills that support i-Construction. Finally, using the latest smartphone surveying solution LRTK as an example, we introduce the benefits of easily implementable high-precision surveying and explore hints for promoting DX.

What is i-Construction (2025 policy and current status)

i-Construction is a measure promoted by the Ministry of Land, Infrastructure, Transport and Tourism since fiscal 2016 to improve productivity at construction sites and reform workstyles. Against the backdrop of structural issues faced by the construction industry—labor shortages due to an aging and declining population, difficulty in passing on skilled craftsmanship, and aging infrastructure—the initiative introduces ICT technologies such as drone surveying and machine guidance (automatic control of construction equipment) to sites to boost productivity. In fact, as ICT construction practices have gradually spread since 2016, productivity in direct government-managed projects is reported to have improved by about 20%. Even small and medium-sized construction companies are increasingly starting with digitizing surveying data and leveraging the cloud, advancing digitalization at their own pace.

From fiscal 2024, efforts have accelerated under the name *i-Construction 2.0*, and more ambitious goals have been set. The biggest point is the "automation of construction sites," with a long-term goal to achieve 30% labor reduction in site work (1.5× productivity) by fiscal 2040. To achieve this, technology development and deployment are advancing around three pillars: automation of construction (expanding autonomous operation and remote control of construction machinery), automation of data linkage (standardization of 3D data use such as BIM/CIM), and automation of construction management (efficiency and unmanning of site supervisory tasks). This new policy also includes workstyle reforms such as improving safety, creating environments in which diverse personnel can thrive, and raising wage levels, presenting a vision to transform the construction industry into a "new construction industry."

Under these policies, principles such as ICT construction as a norm and full application of BIM/CIM are becoming a reality at sites. For example, in ministry-managed projects, ICT construction was introduced in about 86% of earthwork by fiscal 2022, and from fiscal 2024 ICT earthwork began to be ordered in principle.

BIM/CIM (3D modeling) started to be applied in principle from fiscal 2023, and by 2025 full application to all civil engineering works is scheduled at expressway companies.

Furthermore, the expansion of remote presence for on-site inspections (online attendance for inspections), thorough cloud sharing and electronic delivery of construction data, and other i-Construction initiatives are broadening digitalization comprehensively from surveying through design, construction, inspection, and maintenance.

What site DX is required in 2025 (digitization starting from surveying)

"Site DX" refers to efforts to fundamentally transform on-site business processes by introducing digital technologies. The goal is not merely to use tablets, but to optimize information management and construction procedures that previously relied on paper and manual labor through data and IT. Considering the overtime regulations enacted under 2024 workstyle reform laws (the 2024 problem) and the future decrease in the workforce, realization of site DX is increasingly demanded in 2025. To deliver and maintain high-quality infrastructure with limited personnel, it is unavoidable to review inefficient traditional practices and use digital technologies to streamline and reduce labor.

Particularly important in this context is digitization starting from surveying. Surveying is the first step in construction and forms the basis for creating drawings and plans by understanding the site's terrain and structures. If data collected at this initial stage are digitized, they can be used consistently through subsequent design, construction, inspection, and maintenance. Conversely, if surveying results remain only in paper drawings or analog figures, re-entry or re-surveying on-site may be required in later stages, causing rework and reducing productivity.

For example, 3D surveying by drone aerial photography and point cloud measurement by terrestrial laser scanners have spread as methods that acquire detailed on-site data in digital form in shorter time than before. These advanced technologies allow surveying results to be immediately reflected in CIM (Construction Information Modeling) models or earthwork volume calculations and shared between designers and constructors. In other words, centrally managing data digitally from the surveying stage enables seamless connection across subsequent processes and can greatly improve operational efficiency.

As a strategy to promote site DX, "start digitalization from surveying" is effective. In practice, even small and medium-sized enterprises unfamiliar with ICT or DX are increasingly taking the first step by digitizing surveying equipment and software and managing acquired data on the cloud. Small changes—recording measurements on a tablet instead of a field notebook, handling terrain with point cloud data instead of CAD drawings—allow sites to begin digitalization from modest steps, eliminating wasteful work and contributing to workstyle reform. Surveying-led DX is the first step toward transforming the entire site.

The role of smartphone surveying, RTK, and single-person surveying and their penetration in practice

The recently emerged smartphone surveying is an indispensable keyword when discussing site DX. By combining smartphones or tablets with high-precision GNSS receivers, centimeter-class positioning (cm level accuracy (half-inch accuracy)) that previously required specialized equipment can now be achieved easily. The core of this technology is the RTK (real-time kinematic) method. RTK obtains high positioning accuracy by comparing satellite positioning data from a base station and a rover in real time and applying differential corrections—traditionally performed with expensive GPS equipment used by surveying professionals. In recent years, however, by combining smartphones with compact receivers and reference station data over the internet (network-type RTK, etc.), RTK is becoming an accessible technology anyone can handle.

Smartphone surveying is attracting attention for its benefits in labor saving and efficiency. Major advantages include:

• Surveying can be completed by one person: With total stations, surveying required at least two people for measurement and holding rods, but with a smartphone + GNSS, one person can measure their current position. This allows site work to continue despite labor shortages.

• Portability and mobility: Smartphone surveying equipment is compact and lightweight, enabling easy walking around the site to measure required points. It can often measure safely from a secure position in high or hazardous locations, enabling rapid data collection.

• Real-time data sharing: Survey data obtained on a smartphone can be uploaded to the cloud on the spot and shared immediately with office support staff or the client. Sharing data continuously prevents re-measurement and communication errors and speeds up decision-making.

• Low cost and ease of introduction: Compared to dedicated surveying equipment, initial investment is often lower, and using existing smartphones reduces the barrier to adoption. App operation is intuitive, so workers unfamiliar with IT can become proficient in a short period.

• Promotion of data utilization: Since surveying results are stored as digital data, using them later in design and construction management becomes easy. Functions unique to smartphones—geotagged photos, automatic calculation of distances and areas between measured points—provide high-value-added data through functional integration.

This smartphone × RTK single-person surveying is becoming a quiet trend among site practitioners. In fact, moves are seen to equip sites with "one smartphone surveying device per person," enabling anyone to perform surveying quickly when needed. As a result, situations where crews used to wait for the surveying team now often see site personnel performing measurements themselves and immediately verifying and sharing data. Smartphone surveying is used in various practical scenes: shape confirmation at small development sites, recording locations of buried objects in road works, surveying damage at disaster sites, and more. Advanced applications are also emerging, such as displaying design data on a smartphone screen in AR for staking out. The ways to use it on site are expected to expand further.

Consistent data utilization from surveying through construction, inspection, and maintenance

One of the principles of i-Construction is consistent data utilization. This idea links and reuses information obtained at each project stage to improve efficiency. If spatial data obtained during surveying are used as the starting point through design, construction, inspection, and maintenance, redundant re-surveying and data re-entry for each task can be eliminated. In other words, by "using data entered once multiple times," each phase connects seamlessly under a centralized information foundation.

For example, 3D terrain data and existing structure positional information obtained from surveying can be directly applied to creating CIM models for planning and design. Designers can develop construction plans while referencing accurate as-built models, and the resulting 3D design data are handed to constructors to be used as data for machine guidance and as standards for control of final shapes. During construction, sensor data from heavy equipment and measurement data for construction management are continuously accumulated in a cloud-based common data environment, allowing clients and supervising engineers to monitor progress in real time. During inspection, construction data can be used to efficiently check as-built conditions and quality, and after completion the 3D models and surveying data are registered in a maintenance database for use in inspections and repair planning.

To realize this consistent data utilization, data formats and standards must be unified and opened. The government and industry organizations are advancing standardization of BIM/CIM and preparing electronic delivery procedures, and new rules such as "positioning 3D models as contract documents" have been announced. This elevates 3D data from mere reference materials to official information sources, making repeated use in subsequent processes more likely. As site DX progresses, it is also envisioned that completed infrastructure can be represented as a digital twin (a twin model in virtual space) and combined with sensor monitoring data to enable advanced uses such as deterioration prediction and optimal repair planning.

Supporting this series of flows is the aforementioned digital data acquisition from the surveying stage. Obtaining accurate and highly versatile data at the outset enables smooth use in later stages. Conversely, if on-site data contain errors or inconsistencies, subsequent model creation and construction management may be hampered. Therefore, high-precision surveying and data sharing are key to ensuring quality and efficiency in the site DX era.

Human resources supporting i-Construction and changes in on-site skills

As digital technologies permeate sites, the required human resource profiles and skills are also changing. Supporting the i-Construction-era site requires not only traditional craftsmanship but "construction DX personnel" equipped with ICT skills. Specifically, individuals with digital literacy to handle drones, GNSS surveying equipment, and 3D design data, as well as practical civil engineering knowledge and planning ability, are in demand. In other words, engineers with a hybrid skill set of site experience × digital technology are the ideal.

Trends in on-site skills are also evolving. For example, traditional skills such as reading drawings and staking out remain important, but these tasks are increasingly performed on tablets with electronic drawings or using AR technology. In surveying, it is no longer sufficient to just operate transits and levels; mastering RTK-GNSS receivers and point cloud processing software is also necessary. Heavy equipment operators need to understand the control panels of machine-control-compatible machines and execute work according to data. Moreover, the ability to analyze and improve site issues using cloud-based construction history data and IoT sensor information is becoming increasingly important.

To acquire these new skills, human resource development is being actively promoted by companies and the industry as a whole. Training includes hands-on experience with ICT construction operations, basic education in 3D CAD, and on-site training pairing young employees with veterans to ensure intergenerational skill transfer. Veterans apply their abundant on-site knowledge to consider how to use digital tools, while younger workers leverage IT proficiency to propose efficiency improvements—those complementary strengths are being combined. While executive understanding and leadership are essential for DX promotion, cultivating "practically capable DX personnel" from the field is the key to truly embedding i-Construction.

Changes in personnel also affect workstyles and employment at sites. The introduction of remote operation and telework means that not all tasks require long on-site hours. As a result, there is potential to utilize new worker segments such as engineers balancing childcare or caregiving and working, and senior engineers providing remote guidance after retirement. Furthermore, if digitalization reduces heavy and hazardous work, the image of the construction industry may improve, encouraging entry by younger people and women. The combination of diversification of personnel and upskilling of abilities is helping drive i-Construction toward a sustainable industry transformation.

Example of smartphone surveying implementation: LRTK brings easy high-precision surveying

Finally, as a concrete example of smartphone surveying implementation, we introduce the noteworthy solution LRTK. Developed by a startup originating from the Tokyo Institute of Technology, LRTK is a system composed of a compact RTK-GNSS receiver and a smartphone app. By attaching the dedicated receiver to an iPhone or iPad, a device weighing only about 125 g turns a smartphone into a surveying instrument with centimeter accuracy (cm level accuracy (half-inch accuracy)). Its pocketable compactness and the convenience of being able to measure whenever needed are its defining features.

Using the LRTK smartphone app, you can tap a button at the point you want to measure and record latitude, longitude, and altitude with high accuracy. It automatically supports Japan's geodetic systems (global geodetic system, plane rectangular coordinate system, geoid height), so you do not need to worry about troublesome coordinate conversions on site. You can add timestamps and notes to recorded points, and the collected point data can be uploaded to the LRTK Cloud with a single tap. Measured points are plotted on the cloud map so office staff can immediately check results. If multiple points are measured, distances and areas are automatically calculated, enabling necessary on-site calculations to be performed there and then.

Compared to conventional RTK surveying equipment, the markedly affordable price is another major attraction of LRTK. Without needing to purchase expensive equipment for each person, attaching one LRTK unit to each site staff member's smartphone realizes a one-device-per-person surveying tool. LRTK has actually been adopted not only by construction and surveying companies but also by local governments, helping to speedily grasp damage at disaster sites and improve the efficiency of infrastructure inspection. By establishing an environment where "anyone can measure anytime, anywhere," site productivity and the volume of accumulated data will dramatically increase.

The emergence of such smartphone surveying solutions has greatly lowered the barrier to DX. From an era when high-precision positioning was left entirely to specialized contractors, we have moved to one in which anyone on site can measure and utilize necessary information. The important thing is to try introducing digital tools to the site, even with a small first step. Make effective use of easily adoptable smartphone surveying solutions such as LRTK as a trump card for site DX, and link them to productivity improvements and workstyle reforms in construction sites beyond 2025.