How RTK and Unmanned Construction Machinery are Transforming Road Construction Sites:
Efficiency Improvements through ICT Construction

This article takes an average of 2 minutes and 30 seconds to read
Published March 7, 2025

In recent years, improving productivity through the use of digital technologies has become a major theme in the construction industry. Particularly, as labor shortages and the aging of skilled operators become more serious, there is an increasing demand for the promotion of ICT (Information and Communication Technology)-driven construction practices.
In road construction sites, high-precision positioning with RTK and the introduction of unmanned construction machinery (remotely operated or autonomous machines) are gradually replacing traditional labor-intensive methods, resulting in enhanced work efficiency and safety.
In this article, we will provide an overview of the ICT construction practices advancing in the construction industry, explore the relationship between key technologies such as RTK-GNSS positioning and unmanned construction machinery, and discuss the benefits and challenges they bring to road construction. We will also explain the optimal solution, "LRTK," that addresses these challenges.
What is ICT Construction? Digital Transformation in the Construction Industry
ICT construction refers to construction methods that incorporate information and communication technologies, such as positioning and data transmission, into the construction production process. Specifically, it involves using drones (UAVs) and 3D laser scanners for surveying, creating 3D design data, and applying RTK-GNSS for machine guidance and machine control (automatic or semi-automatic operation of construction machinery). These digital technologies are utilized consistently throughout all stages—from surveying and design to construction and inspection.
Since 2016, the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) has been promoting the full-scale adoption of ICT as part of its i-Construction initiative, aiming to significantly improve productivity at construction sites and create more attractive and engaging workplaces.
The introduction of ICT construction has been reported to deliver various benefits compared to traditional construction methods.
For example, in one demonstration project, the use of ICT earthwork led to notable outcomes such as (1) a reduction in the number of required workers, (2) shorter construction periods, and (3) improved construction accuracy. These results are attributed to the digitalization of processes, which reduces the need for manual labor and rework, enabling high-precision construction without relying on personal experience or intuition. Road construction sites, which traditionally depended on the skills of seasoned workers, are now transforming into environments where anyone can perform efficient and high-quality work thanks to digital innovation.
Relationship Between RTK-GNSS Positioning and Unmanned Construction Machinery
At the core of ICT construction is RTK-GNSS (Real-Time Kinematic GNSS), a high-precision satellite positioning technology. RTK refers to a method that applies the real-time differential data between GNSS signals observed by a base station and a rover, enabling centimeter-level positioning accuracy. Specifically, the typical positioning accuracy is about 2–3 cm horizontally and about 3–4 cm vertically, which is significantly more precise compared to the several-meter errors associated with standalone positioning (standard GPS).
With this high-precision RTK positioning, surveying and equipment positioning at road construction sites become significantly more accurate and efficient.
On the other hand, unmanned construction machinery refers to construction equipment that operates through remote control or autonomous systems without an onboard operator. Machines such as bulldozers and excavators (backhoes) are equipped with GNSS receivers and orientation sensors, and operate by continuously comparing their current position with the target coordinates defined in 3D design data. With high-precision RTK-GNSS positioning, these machines can automatically adjust the position of blades or buckets without human intervention. For example, in the latest GNSS-controlled bulldozers, the blade is automatically controlled to match the predefined design elevation, allowing the operator to focus solely on forward and backward movements while achieving precise grading work. This eliminates the need for manual setting of height markers (“batter boards”) and the fine-tuning based on visual reference, enabling even less experienced operators to achieve consistent and high-quality finishes.
In this way, the high-precision positioning of RTK-GNSS and the automatic control technology of unmanned construction machinery are utilized together as a set. Because RTK enables real-time tracking and control of heavy machinery positions, remote operation and autonomous driving have become a reality. At road construction sites, aside from transport by dump trucks and minor manual tasks, the entire process from surveying to construction can now be completed using digital data and unmanned machinery. This trend not only enhances safety in hazardous work environments but also contributes to reducing quality variation and improving work efficiency.
Benefits of Road Construction Using Unmanned Machinery
Introducing ICT construction that combines RTK-GNSS with unmanned construction machinery brings numerous advantages to road construction. The key benefits are summarized below.
Traditionally, construction required setting up batter boards and repeatedly surveying to check and adjust the construction surface. However, with ICT construction, these tasks are no longer necessary, allowing operators to focus solely on maneuvering the machinery. As illustrated in the conceptual diagram below, correction data is received from satellites or base stations (via GPS or TS*), and the machine’s blade is automatically controlled based on the difference between the target surface in the digital design data and the current blade position. This enables high-precision grading without manual fine-tuning. (*TS: Total Station. In environments where GNSS signals cannot be received, the system can switch to optical distance measurement for positioning.)
So, what specific benefits can be achieved through ICT construction using unmanned machinery and RTK technology? The key advantages are summarized below.
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Labor and Time Savings in Pre-Construction Surveying and Batter Board Work: With drone surveying and machine guidance, tasks such as surveying existing conditions and checking finished surfaces become more efficient. Since there is no longer a need to manually install and manage numerous batter boards, a significant reduction in labor is achieved. In fact, one case study showed that the time required for the initial ground-breaking survey was reduced from an average of 17.7 days with traditional methods to just 2.7 days using ICT construction—resulting in a 73.7% time savings. This acceleration in surveying leads to earlier construction starts, directly contributing to increased productivity.
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Shortened Construction Periods and Increased Productivity: By reducing the burden on heavy machinery operators and minimizing interim inspections, construction speed is significantly improved. For example, in a large-scale earthwork project evaluated by the Ministry of Land, Infrastructure, Transport and Tourism, a project that traditionally took 63 days was completed in just 52 days using ICT construction—achieving an 11-day reduction in schedule, or about 17% shorter. Additionally, since machinery no longer needs to be repeatedly stopped to check batter boards, operational efficiency increases, resulting in higher daily output. Some reports indicate productivity improvements of around 30%. Compressing the overall construction schedule in this way also leads to reductions in labor and indirect costs.
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Improved Construction Accuracy and Quality: Since the position and working height of the machinery are constantly compared with digital design values, there is less chance of errors even in tasks that traditionally relied on intuition or experience. With machine control, the movements of blades and buckets can be automatically adjusted in real time, allowing construction to proceed with consistent precision according to the design. Eliminating the need for batter boards also reduces the risk of deviation from reference points, and inspections have confirmed high accuracy in the finished work. The ability to maintain consistent quality regardless of operator skill level greatly contributes to achieving the required flatness and height precision in road construction.
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Relaxation of Operator Skill Requirements: With automated control and operation support for heavy machinery, reliance on highly skilled operators is reduced. For example, tasks such as slope shaping, which previously required veteran operators, can now be performed with high precision even by less experienced workers thanks to machine guidance support. This helps address the labor shortage at construction sites by reducing the time needed for skill transfer and workforce training. In the future, it is expected that younger operators will be able to deliver results comparable to seasoned professionals by effectively utilizing ICT-equipped machinery, positively impacting both the shortage of skilled labor and the preservation of technical expertise.
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Enhanced Safety: The use of unmanned construction machinery offers significant safety benefits on-site. With remote operation and automated control, workers no longer need to enter hazardous areas where heavy machinery is in operation. Traditionally, during slope (embankment) construction, workers had to signal near the equipment or install batter boards, exposing them to risks of falling or collisions with machines. ICT construction greatly reduces these dangers. Furthermore, in disaster recovery sites or areas with a risk of collapse, the ability to operate machinery remotely without placing personnel onboard directly contributes to ensuring safety. Ultimately, this helps prevent occupational accidents, raises safety awareness, and fosters a work environment where tasks can be performed with greater peace of mind.
As described above, ICT construction using RTK and unmanned machinery delivers superior results in all aspects—efficiency, quality, and safety—compared to traditional methods. Road construction, in particular, typically requires a wide work area and a large workforce, but with the introduction of ICT technologies, it is becoming possible to carry out high-quality work quickly and efficiently with fewer personnel.
Challenges and Solutions in Using RTK
While ICT construction and RTK utilization offer numerous benefits, several challenges have been identified when it comes to implementation and operation on-site. Below, we examine the main issues and explore possible solutions to address them.
Communication Constraints and Countermeasures
To operate RTK-GNSS in real time, a communication link (such as radio or internet) is typically required to transmit correction data from the base station to the rover. Similarly, when remotely operating unmanned construction machinery, a stable network is necessary for transmitting video from the site and for control communication. However, many road construction sites are located in mountainous or remote areas where cellular and network coverage is unstable or unavailable, making communication a potential bottleneck. In fact, civil engineering and construction sites often face situations where “cellular signals are unavailable,” which has posed challenges for the stable operation of high-precision positioning.
One solution to this issue is to diversify the methods for obtaining GNSS correction data. For example, by using satellite-based augmentation services that do not rely on cellular networks, correction data can be received even in areas without mobile coverage. In Japan, this is made possible through the “CLAS (Centimeter-Level Augmentation Service)” provided by the Quasi-Zenith Satellite System (QZSS), known as Michibiki.
By using a CLAS-compatible receiver, correction data can be received directly from satellites, enabling RTK-level high-precision positioning even in mountainous or remote areas. In fact, products like LRTK, which will be discussed later, utilize CLAS to achieve stable centimeter-level positioning even at sites without cellular coverage, providing users with a high level of confidence and reliability.
In addition, other approaches include setting up local relay stations (such as mobile communication units or Wi-Fi access points) at the site to expand the coverage area, or using dedicated communication methods like UHF digital radio to transmit correction data. The key is to combine multiple communication methods to ensure redundancy, making it possible to maintain uninterrupted RTK positioning regardless of the site environment.
Challenges in Creating and Managing 3D Data
In ICT construction, a 3D design model must be created from design drawings before construction begins, and this model is then loaded into the construction machinery for use on-site. Creating this 3D data requires specialized software and expertise, which can pose a new burden for traditional construction companies. If the company lacks the capability to handle this in-house and must outsource the task, waiting for the completed data can delay the overall schedule. In fact, trial projects involving ICT construction have reported concerns such as “uncertainty about new processes like 3D data creation” and “work was interrupted while waiting for outsourced data to be delivered.”
One solution to this challenge is to develop an in-house system for creating and managing 3D data. Even if the process initially relies on outsourcing, gradually shifting to in-house data creation with each project helps staff build their skills and improves overall efficiency. Fortunately, there is now a wide range of software and support services available for 3D model creation, including tools that can semi-automatically convert 2D drawings into 3D models. Additionally, in some cases—such as public road construction—clients (such as government agencies or prime contractors) have begun providing pre-prepared 3D design data to support implementation.
Standardization of 3D design data is being promoted by national and local governments, and in the future, an environment may be established where contractors no longer need to create the data themselves. Moreover, surveying instruments that simplify processes such as localization (converting to local site coordinate systems) are becoming available, gradually lowering the barriers from data creation to implementation. What’s essential is to develop digital talent within the company to accumulate expertise, while also building a system that enables smooth 3D data operations by leveraging external support—such as software providers or assistance from project owners—when necessary.
Cost and Skill Acquisition Challenges in Implementation
When introducing new technologies, challenges related to cost and workforce development cannot be overlooked. ICT-compatible construction machinery is more expensive than conventional machines, and initial investments are also required for RTK-GNSS surveying equipment and communication devices. For small to mid-sized civil engineering companies, acquiring all of this at once can be a significant burden. Additionally, it takes time and training for on-site staff to become proficient with new systems. Some experienced workers may feel uneasy with digital equipment, expressing concerns such as “confusion over tasks that didn’t exist before” or “uncertainty about whether they can use the technology effectively in the field.”
To address these challenges, a phased implementation approach can be effective. If initial costs are a burden, companies can start by using rental or leased equipment and gradually introduce ICT construction in specific phases or sections of a project. Additionally, taking advantage of government subsidies or incentive programs from the Ministry of Land, Infrastructure, Transport and Tourism—such as bonus points in bidding for projects that adopt ICT construction—can help improve cost-effectiveness.
For skill development, it is important to utilize training sessions and workshops offered by manufacturers and industry organizations, and to introduce ICT construction in trial runs during actual projects to build in-house expertise. Fortunately, once users become familiar with ICT construction technologies, they often find them so convenient that they say they could never go back, as these technologies greatly reduce the workload on-site.
It is also important to reduce resistance by organizing in-house study sessions that involve both veteran and younger employees, and by sharing successful examples from other projects. Additionally, GNSS equipment, which used to be expensive, has recently become more compact and affordable. Low-cost RTK receivers that can be used in conjunction with smartphones or tablets are now available. By utilizing these more accessible and budget-friendly tools, companies can significantly lower the initial cost of implementation.
RTK Utilization with LRTK
In light of the challenges mentioned above, our company offers a solution called "LRTK" to make RTK-GNSS more accessible and reliable for on-site use. LRTK is a system centered around a compact, high-precision GNSS receiver that can connect with smartphones, enabling centimeter-level positioning without the need for expensive dedicated equipment. For example, our LRTK Phone series features a compact device with an integrated antenna and battery, allowing RTK positioning simply by attaching it to an iPhone or similar device.
Thanks to wireless Bluetooth connectivity, no complicated cables are required. The device can be used for mobile surveying while walking, or mounted on a pole or tripod for stationary positioning.
Traditionally, RTK surveying required stationary GNSS receivers or large base station setups. LRTK makes it possible to achieve RTK surveying with "one RTK device per person," allowing everyone from site managers to skilled workers to obtain high-precision positioning data anytime, as needed.
Furthermore, LRTK supports CLAS, the augmentation signal provided by Japan’s Quasi-Zenith Satellite System (QZSS), known as Michibiki. This allows for stable positioning even in mountainous areas or near underground structures where cellular signals are unavailable. In response to the communication challenges mentioned earlier, LRTK can continuously receive correction data directly from satellites, ensuring uninterrupted positioning without degradation in accuracy—even outside of mobile network coverage.
LRTK also supports cloud-based data management, making it easy to instantly attach accurate location information to point cloud data and photos collected on-site and share them in real time. This enables immediate quality checks and progress management of areas developed with unmanned machinery, while allowing real-time information sharing with headquarters or project owners. Developed under the concept of “RTK for everyone on-site,” LRTK strongly supports precision management in ICT construction without requiring special skills or complex setup.
Let’s work together to create safer and more efficient road construction sites by harnessing the power of the latest technologies.
Dramatically Improve Surveying Accuracy and Work Efficiency on Site with LRTK
The LRTK series enables high-precision GNSS positioning in the fields of construction, civil engineering, and surveying, allowing for significant reductions in work time and substantial improvements in productivity. It also supports i-Construction, promoted by the Ministry of Land, Infrastructure, Transport and Tourism, making it the ideal solution for driving digitalization in the construction industry.
For more details about LRTK, please visit the links below:
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What is LRTK | Official LRTK Website
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LRTK Series | Device List Page
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Case Studies | Examples of Use in Construction Sites
If you have any questions about the products, need an estimate, or wish to discuss implementation, please feel free to contact us via the inquiry form below. Let LRTK help take your site to the next level!