AR Civil Engineering Tackling Labor Shortages: Improve On-site Efficiency through Labor Saving

Table of Contents

• The worsening labor shortage problem in the construction industry

• The transformation digitalization and DX bring to worksites

• What AR technology is expected to do in civil engineering

• Concrete examples of AR use: from construction support to surveying

• Effects and benefits brought by AR adoption

• Challenges and future prospects of AR adoption

• Simplified surveying with LRTK

• FAQ

The worsening labor shortage problem in the construction industry

In recent years, labor shortages and the aging of skilled workers have become serious problems in Japan's construction and civil engineering industries. The number of construction workers, which was about 6.85 million in the late 1990s, has now fallen to around 4.8 million—a decrease of roughly 30%. The age composition of skilled workers is also notably unbalanced: those aged 55 and over account for more than 30% of the workforce, while those 29 and under make up only about 10%. The so-called "3Ks (kitzui, kitanai, kiken)"—literally "difficult, dirty, dangerous"—image of the work and the custom of long working hours deter younger generations, resulting in few new entrants and high early turnover, which accelerates the aging of on-site personnel.

This ongoing labor shortage and aging are beginning to hinder on-site skills transfer. While the veteran generation is retiring in large numbers, there are insufficient young workers to inherit their advanced skills and know-how. In busy worksites, there is little time for training newcomers, and the craftsman skills based on extensive experience tend to become person-dependent. Young workers often feel unsure about what to do and how to do it, sometimes losing confidence before gaining experience. Meanwhile, veteran instructors are constantly overwhelmed and have little spare capacity, increasing the risk that valuable knowledge will disappear without being passed on. If this continues, a break in skill continuity could occur, potentially reducing productivity and safety at construction sites.

The transformation digitalization and DX bring to worksites

One of the keys attracting attention to break this crisis is digitalization of construction sites, commonly called "civil engineering DX (digital transformation)." This involves not merely introducing the latest IT devices but reforming business workflows through digital technologies to dramatically improve productivity. In practice, ICT technologies are being used across many processes from surveying to design, construction, and maintenance. Examples include drone-based 3D surveying, automated control of construction equipment, the adoption of BIM/CIM (design and construction using 3D models), remote sharing of site footage, and AI-based image analysis for infrastructure inspections—digital technology is changing how sites operate.

Since the Ministry of Land, Infrastructure, Transport and Tourism proposed *i-Construction* in 2016, it has strongly promoted ICT use in public works. ICT-equipped machinery, drone surveying, and tablet-based plan viewing have been actively introduced, and from fiscal 2020 onward the use of new technologies has been made essentially mandatory for directly managed projects, accelerating the DX trend across the industry. Furthermore, in 2024 the construction industry will be subject to limits on overtime work (the so-called "2024 issue"), making labor-saving productivity improvements more urgent than ever. DX is not only a quick remedy for labor shortages but also an essential measure for workstyle reform.

The effects of DX go beyond merely supplementing labor shortages. Digitalization enables improved construction efficiency and quality and strengthened safety management, and adopting the latest technologies helps create smarter workplaces that appeal to younger talent. Dispelling the image of an "old-fashioned industry" and providing a field where the digital generation can thrive offers major benefits for recruitment and retention. In short, construction DX is an important initiative that supports the industry's future from multiple angles: productivity improvement, workstyle reform, and talent development.

What AR technology is expected to do in civil engineering

Among many digital technologies, AR (augmented reality) has recently attracted particular attention. AR is a technology that overlays digital information on real-world images and can be used via smartphones, tablets, or smart glasses. By superimposing virtual information such as design drawings, 3D models, and guidelines onto live site footage through a camera, users can see "things that shouldn't be there now" as if they existed in their field of view. While VR (virtual reality) immerses users completely in a virtual space, AR differs in that it adds virtual information to the real environment. Because AR allows users to reference information while grasping site conditions, it is seen as a technology well-suited to civil engineering and construction tasks.

Why is AR expected to help resolve labor shortages and save labor? The reason is that AR can intuitively compensate for on-site work's "hard-to-understand" aspects. Tasks that traditionally relied on drawings and strings can be guided by AR displays of the completed form, eliminating the need to depend on skilled workers' intuition or experience. For example, if a model of a structure or reference lines are projected onto the ground as designed, position and elevation discrepancies become immediately visible. Even for first-time tasks, workers can visually understand "where and how much to excavate" or "to what height to place fill," enabling inexperienced workers to proceed confidently and accurately. In other words, AR has the potential to realize "site capabilities that do not depend on individuals" by digitalizing the craftsmen's skills and spatial images that existed in veterans' heads and providing them to the site in a shareable form.

Furthermore, AR's strength of real-time information display and sharing makes it useful for safety management, remote support, and training. AR can display locations of hazards or buried utilities to warn workers, or experts can annotate live site footage to provide remote guidance—various applications are possible. With its wide range of potential uses, AR technology is increasingly expected to be one of the trump cards that will dramatically improve productivity and safety on future civil engineering sites.

Concrete examples of AR use: from construction support to surveying

Here are some concrete examples of how AR is being used in civil engineering.

• Work support through construction navigation: Technology that navigates construction locations on site using AR. When a smartphone or tablet is held up, lines or shapes as in the design are displayed over the camera image, and workers can use them as a guide while working. In layout marking work, instead of looking at drawings, workers can mark along the reference lines displayed in AR, enabling accurate positioning even for inexperienced personnel.

• Real-time confirmation of as-built data: An example where as-built (finished) data acquired after construction is immediately displayed in AR for on-site confirmation. Using a tablet’s LiDAR scanner or surveying equipment attached to a smartphone to perform 3D surveying of the surroundings, the resulting point cloud data can be overlaid with the design model. A color-coded heat map makes differences from the design obvious at a glance, allowing immediate judgment on "where and how much to correct" before concrete sets.

• Remote support and remote collaboration: AR can connect the site to the office, allowing remote expert technicians to support on-site work. Systems have emerged where experts can write instructions or markings in real time on the footage shown by on-site workers. As a result, appropriate advice can be given without visiting the site, enabling the knowledge of veterans to be applied to multiple sites simultaneously despite labor shortages.

• Use for skills acquisition and training: AR/MR technologies are also effective for training young workers. Trainees can experience safety education content in VR or practice in a safe environment by displaying AR-based simulated construction scenarios to gain field sense that cannot be obtained from classroom study. On actual sites, AR can act as a navigator so that newcomers can perform tasks without relying on seniors, increasing autonomy and accelerating experience accumulation.

Effects and benefits brought by AR adoption

By introducing AR technology to sites, the following concrete benefits can be obtained.

• Improved work efficiency: Following AR guidance reduces rework and increases the probability of correct execution on the first attempt. It saves time spent on alignment checks and surveying, enabling small crews to progress quickly through tasks, which in turn shortens construction periods and reduces labor costs.

• Improved construction accuracy and quality: AR can greatly reduce construction errors caused by misreading drawings or measurement mistakes. Working while always viewing the design lines and elevations improves finish accuracy and eliminates the need for veteran-based fine adjustments. Reducing rework from quality defects also suppresses unnecessary operation of materials and heavy equipment.

• Enhanced safety: Visualizing hazard areas in AR and accurately indicating work procedures prevents accidents caused by human error or misunderstandings. An environment where workers can move without hesitation contributes to improved safety awareness. Reducing repetitive heavy work and night shifts also helps secure safety by lessening labor burdens.

• Independence of young workers and skills transfer: Even inexperienced young workers can be guided by AR as an "invisible senior," enabling them to proceed with tasks based on their own judgment. Not having to ask for instructions each time builds confidence and accelerates skill acquisition through practice. For veterans, the burden of giving minute instructions is reduced, allowing them to focus on more important points in training. As a result, knowledge sharing progresses across the site and smooth generational transitions are facilitated.

• Activated communication: Sharing completed images and measurement data via AR makes it easier for stakeholders to share common understanding. Everyone on site can view the same screen and discuss adjustments like "let's lower this a bit" in real time, and visual materials can be used directly to explain to clients. Smooth communication helps prevent mistakes and build trust.

• Improved retention and recruitment effect: Integrating digital technology on site itself helps create an attractive workplace for younger workers. A site that masters the latest gadgets gives a positive impression of being "cool" and "driving change from within," which is expected to boost motivation and help attract and retain skilled personnel.

Challenges and future prospects of AR adoption

Despite its many benefits, several challenges have been pointed out regarding on-site AR adoption. First is the issue of initial cost. High-end AR glasses and dedicated devices have traditionally been expensive, posing a hurdle for small and medium-sized construction companies. Also, using AR effectively requires on-site 3D data and accurate positioning information, so integration with existing operations and data preparation must be arranged. Some veterans may have an aversion to IT, so sufficient training and support for site staff are indispensable in the early stages of adoption. Moreover, technical challenges remain, such as ensuring device reliability and durability to operate stably in harsh outdoor environments and under all-weather conditions.

However, in recent years these challenges have steadily been addressed. Hardware is becoming smaller and cheaper, and AR can now be handled with general smartphones and tablets. For example, accessible AR surveying systems that combine high-precision GNSS receivers and LiDAR sensors attachable to smartphones have appeared, allowing intuitive operation without specialized surveying knowledge. User interfaces are being simplified based on site feedback, reaching a level where people unfamiliar with digital tools can handle them with a little training. As high-speed communication infrastructures like 5G advance, real-time remote support linked to the cloud and use of large-capacity data will become even easier.

Overall, AR technology is evolving toward more site-friendly forms year by year. While it may seem difficult at first, it is recommended to introduce it experimentally in a small site or department to verify its effects and usability. Hands-on experience deepens site staff understanding and makes gradual company-wide rollout easier.

Simplified surveying with LRTK

A representative example of the accessible AR surveying systems mentioned above is LRTK. LRTK is an all-in-one surveying and AR system that uses a compact high-precision GNSS receiver attached to a smartphone or tablet. By launching a dedicated app and simply holding the device up at the site, a single operator can easily perform the sequence of "see, measure, and record" on the spot. Even inexperienced newcomers can perform advanced surveying tasks quickly and accurately with LRTK.

The main functions of LRTK include the following. First, a single person can perform high-precision surveying immediately with just a smartphone. The obtained point cloud data and measured coordinates are automatically linked to geographic coordinates, allowing you to generate as-built heat maps by comparing with design data or perform volume and area calculations with a single tap. Photos taken with the smartphone are automatically tagged with location and orientation and saved to the cloud instantly. All acquired data (coordinates, point clouds, photos, etc.) are synchronized to the cloud in real time, so results can be checked from office PCs immediately. Remote support is also possible, where a distant veteran technician views cloud data and instantly gives feedback like "excavate a bit more here." Additionally, the cloud service can automatically create graphs and output reports from uploaded data, greatly streamlining the flow from surveying to deliverable production.

LRTK's strengths are its ease of use and versatility. The equipment consists only of a compact receiver that fits in a pocket and the smartphone you already use. People without surveying expertise or those who cannot carry heavy equipment can operate it without burdening the site. On actual sites, young employees have begun to be entrusted with laying out batter boards and performing as-built measurements while holding an LRTK in one hand. Tasks that used to rely on surveyors are becoming accessible to anyone who wants to participate, allowing measurement operations to continue even amid labor shortages. In one field, a task that used to take two-person teams half a day for as-built measurement was reported to be completed by one person in about one hour after introducing LRTK. Cloud-based remote support from veterans to younger workers also makes it easy to receive appropriate advice in real time from afar, enabling new forms of skills transfer that were previously difficult. Introducing the latest digital tools also raises motivation among young workers, fostering a sense of ownership like "our generation will change the site."

Thus, LRTK is a reliable tool that helps create an environment where anyone on site can make full use of digital technology. It can be a powerful partner for putting the AR-based work guidance and as-built data uses introduced in this article into practice on real sites. Because it is designed to be usable without specialized knowledge, why not try it on a small project first to experience its usefulness?

FAQ

Q. What is the difference between AR and VR? A. AR (augmented reality) overlays digital information on real-world imagery, allowing you to obtain additional information while viewing site conditions. VR (virtual reality), on the other hand, immerses the user completely in a virtual space. For civil engineering site work, AR is often more suitable because it allows users to reference information while surveying their surroundings.

Q. What equipment and preparations are needed to introduce AR? A. Basically, you can start with a smartphone or tablet with a camera that can run an AR app. However, for accurate alignment on large outdoor sites, high-precision GPS (GNSS), dedicated markers, and 3D design data may be required. Recently, more convenient equipment such as GNSS receivers and 3D scanners that attach to smartphones has become available, so it is important to choose a system that matches your company's needs.

Q. Can older workers who are not good with IT use AR effectively? A. Yes—recent AR systems are designed to be intuitive. Many can be used simply by pointing a smartphone camera, without complicated operations. They may be puzzled at first, but in many cases they become accustomed to the system by trying it on site with support from younger colleagues. Users often say that AR, which operates by "what you see is what you do," is actually easier to understand than reading drawings.

Q. Is the cost of introducing AR worth the effect? A. Initial and license costs are required, but the benefits can outweigh them. For example, time spent on surveying and inspections can be greatly reduced, and fewer reworks due to mistakes lead to cost savings. As a result, ROI (return on investment) tends to be high. Also, inexpensive smartphone-app-based services have appeared recently, so it is becoming possible to use AR without making large investments as in the past.

Q. How widespread is AR technology on sites? A. Currently, AR is at the trial-introduction stage in some advanced construction companies and projects, but adoption is increasing year by year thanks to national promotion. Since initiatives like i-Construction, AR has received attention alongside drones and ICT-equipped construction machinery, and case studies have been reported in construction management and surveying. Over the next few years, as know-how accumulates and cost barriers fall, it is expected to spread rapidly to small and medium-sized sites.