Can AR Visualization of Underground Utilities Prevent Construction Errors? Effects on Inspection Accuracy and Consensus Building

Table of Contents

• Introduction

• What Is AR Visualization of Underground Utilities?

• Effects of AR on Preventing Construction Errors

• Improved Inspection Accuracy through AR Use

• AR-Driven Smooth Consensus Building

• Challenges and Prospects for AR Adoption

• Summary

• Simple Surveying with LRTK

• FAQ

Introduction

On construction sites, it is always necessary to be aware of infrastructure buried underground—such as water and sewer pipes and power cables—that are not normally visible. If the locations of these underground utilities are not accurately known, excavation can accidentally damage pipes or structural elements can be placed in the wrong positions, leading to construction errors. Traditionally, teams have addressed this by checking drawings in advance and marking the ground, but human error cannot be completely eliminated. One promising new approach to solve these problems is AR (augmented reality) visualization of underground utilities. If pipes and other subsurface elements can be displayed as if the ground were transparent through a tablet or smartphone, it could help prevent mistakes during construction. This article answers that question by examining the effects of AR visualization of underground utilities from the perspectives of “preventing construction errors,” “improving inspection accuracy,” and “promoting consensus building.”

What Is AR Visualization of Underground Utilities?

So what exactly is AR visualization of underground utilities? Simply put, it is the digitization of position information for buried pipes and cables and overlaying that data onto the real-world view. On site, dedicated AR apps are used on tablets or smartphones. When you point the camera at the ground, the screen displays the real scene with CG models or lines showing the positions of pipes and structures that should be underground, creating the illusion that you can see through the ground.

This mechanism allows workers to intuitively “see” and confirm buried items that should not be visible. Without relying on paper drawings or spray markings on the ground, personnel can understand the spatial relationships of underground infrastructure through the device screen, greatly improving both safety and efficiency on site. For example, instead of memorizing from drawings that “a gas pipe runs around here,” a real-time route of the gas pipe displayed on the actual ground makes the situation obvious to everyone.

To display AR accurately, however, the device’s position and orientation must be measured with high precision. Standard GPS can produce errors on the order of several meters (several ft), which is insufficient for construction use. Therefore, technologies that reduce errors to within a few centimeters (a few in) are used—such as high-precision positioning called RTK-GNSS (real-time kinematic) and correction information from reference stations. In environments where GNSS cannot be used, such as indoors or in dense high-rise areas, other alignment methods are used, such as SLAM (simultaneous localization and mapping) using camera imagery or correction via installed QR markers. By combining these advanced positioning technologies with 3D data, AR display of underground utilities on construction sites is becoming a practical reality.

Effects of AR on Preventing Construction Errors

How exactly does AR visualization of underground utilities help prevent construction errors? The primary effect is a reduction in the risk of incorrect excavation or pipe damage. Traditionally, to identify buried utilities on site, workers measured distances on drawings and marked them on the ground. However, markings can shift or fade, requiring re-surveying, and during actual heavy equipment operations operators sometimes rely on feel for depth and position, which can result in contact with buried pipes and accidents.

With AR visualization, workers can visually identify hazardous subsurface locations in advance, significantly reducing such human errors. For example, if the route of underground gas or water pipes is shown on a tablet screen, workers can immediately see where to avoid excavating. Incidents like “accidentally cutting an existing pipe” would likely decrease. For heavy equipment operators, following AR-displayed guide lines provides reassurance that digging along the guide is safe, reducing unnecessary delays caused by excessive caution.

Another important point is the ability to detect misplacement of installed elements on the spot. AR can overlay not only existing items but also design models of structures to be installed. For instance, when placing a foundation underground, projecting the completed model onto the site during work allows real-time confirmation that placement is not deviating from the plan. Even slight deviations will appear as mismatches between the real object and the model in AR, enabling immediate detection without later comparison with drawings. In this way, errors in position and dimensions that commonly occur during construction can be discovered on the spot and rework avoided, which is a major benefit. As a result, construction quality improves and rework is reduced, contributing to shorter schedules and lower costs.

Improved Inspection Accuracy through AR Use

AR visualization technology is effective not only for preventing mistakes during construction but also for improving accuracy in post-construction inspections and maintenance. When checking the as-built conditions or the health of infrastructure, traditional methods often involve comparing site conditions with drawings and measurement instruments and relying on visual inspection and experience to find problems. With AR, because you can overlay data onto the actual scene, even minor defects are less likely to be overlooked.

For example, in periodic inspections of bridges or tunnels, overlaying past condition survey data and repair histories in AR onto the current scene enables pinpointing of deterioration locations. If a crack has been recorded, an AR marker placed at that position makes it easy to find the exact spot on site, and if a new crack has formed it can be compared with previous data immediately. Similarly, when comparing as-built conditions with design drawings for buildings or structures, AR visually reveals any discrepancies between the two. If the location of a column or wall differs even slightly from the design model, the screen will show the offset, allowing you to notice millimeter-level errors (mm, about 0.04 in) that conventional measurements might miss.

By improving inspection accuracy in this way, the exact repair locations can be identified, avoiding excessive work or unnecessary fixes and thus reducing costs. For example, in the maintenance of buried pipes that previously required excavating a wide area to check just in case, AR can identify the exact buried locations so only a limited area needs inspection. Inspectors also no longer need to carry paper drawings and constantly match their current position; they can efficiently check by holding up the device on site. With AR use, inspection work becomes data-driven and smarter, enabling safe, reliable inspections with minimal oversights.

AR-Driven Smooth Consensus Building

In addition to visualizing underground utilities, adopting AR technology has a major effect on consensus building among site stakeholders. Construction requires communication among many stakeholders—contractors, clients and supervising authorities, and even local residents. Traditionally, this communication has relied on design drawings, renderings, and verbal explanations. However, drawings and text alone often fail to fully convey the site image, leading to misunderstandings like “this is not what I expected” or “the explanation is unclear,” which can impede consensus building.

With AR, because you can directly project completed images and the state of utilities onto the real scene, all stakeholders can share the same visual information. For example, when explaining to a client before construction, displaying a 3D model of the planned structure over the actual site on a tablet lets the client see the future completed form with their own eyes. Scale and relationships with the surroundings that are difficult to convey in words or drawings become obvious, preventing misunderstandings such as “this is not what we envisioned.” As a result, the time required to reach agreement can be greatly reduced.

Consider a case where design changes become necessary during construction. Normally, explaining changes on drawings and gaining client understanding can take time. But if you project a 3D model of the proposed change onto the site with AR, the client can intuitively grasp the post-construction appearance and is more likely to accept the change. This visual sharing beforehand reduces losses such as “explanations take so long that work cannot proceed until agreement is reached.”

AR is also valuable for onsite inspection attendance during construction. For instance, in road works near existing buried utilities, showing in advance via AR the protective measures taken for buried utilities allows facility managers (the owners of the utilities) to confidently permit the work. In one Ministry of Land, Infrastructure, Transport and Tourism project, using a GNSS-enabled AR system to confirm the clearance between buried pipes and the work area in real time eliminated the need for conventional ground marking and made the inspection meetings smoother because participants could “explain while looking at the screen.” This is a good example of how AR-driven visualization of the site contributed to building trust with clients and related agencies.

Thus, AR technology streamlines the consensus-building process itself. If AR screens and collected data are shared via the cloud, stakeholders in remote locations can grasp the situation in real time without visiting the site. In the future, visualization via AR combined with high-precision positioning may become the standard for consensus building. From clients to site workers, everyone could view the same AR imagery during meetings and make decisions immediately—such a future for construction sites is becoming realistic.

Challenges and Prospects for AR Adoption

Although AR visualization offers many benefits, several challenges must be addressed for full-scale field adoption. First is the need to prepare high-accuracy data and positioning environments. If AR-displayed underground utility information is based on outdated drawings or inaccurate records, the visualization will be shown in the wrong place and could even create hazards. Therefore, accurately surveying the locations of utilities beforehand and creating 3D models is indispensable. As noted earlier, device self-positioning must achieve centimeter-level accuracy; without that, the mismatch between reality and virtual objects becomes large and impractical. However, high-precision GNSS positioning requires specialized knowledge and equipment, and this poses a high barrier on typical sites.

Second, site staff skills and acceptance are also challenges. In sites lacking personnel familiar with handling 3D data such as BIM/CIM or operating the latest equipment, newly introduced AR systems may not be used effectively. Especially during initial adoption, equipment preparation, calibration, and data setup can take time, leading some to prefer “the conventional method is faster.” For this reason, it is important that systems be user-friendly so anyone on site can operate them intuitively and that sufficient training be provided before introduction.

In response to these challenges, recent technological advances are beginning to provide solutions. For positioning, as described later, easy-to-use RTK-GNSS devices have emerged, enabling centimeter-class positioning even without specialist engineers. Also, by establishing mechanisms to share the latest data on the cloud, omissions in drawing updates can be prevented. Combined with the Ministry of Land, Infrastructure, Transport and Tourism’s promotion of *i-Construction*, the groundwork for adopting digital technologies on site is being laid. With more pilot projects and case studies, AR-driven construction DX (digital transformation) is steadily progressing.

Looking ahead, standardization and generalization of AR are expected. What was once limited to large projects or leading companies could eventually become a common tool even on small and medium-sized sites. Reports from trial sites already indicate “improved safety and productivity” and “reduced rework,” and site evaluations are positive. If this momentum continues and the industry increasingly accepts AR, it will contribute to major reductions in construction errors and workstyle reforms.

Summary

As discussed above, AR visualization of underground utilities offers wide-ranging benefits—from preventing construction errors to improving inspection accuracy and smoothing stakeholder consensus building. Making the invisible visible eliminates safety risks and work inefficiencies in advance and facilitates smoother on-site communication—potentially changing conventional practices on construction sites. Of course, AR requires preparatory work such as high-precision data and equipment, but technological innovation is lowering these barriers. Recently, solutions have emerged that allow anyone to perform centimeter-level positioning (centimeter-level positioning (half-inch accuracy)) and AR display with a smartphone, making site adoption easier.

In conclusion, AR visualization of underground utilities can be an effective means to prevent construction errors. Moreover, it provides major benefits in improving inspection and maintenance quality and facilitating smooth communication with stakeholders such as clients. This technology, which fuses digital data with on-site operations, can be regarded as one of the pillars of the construction industry’s DX. In the near future, it may become commonplace to see workers holding up tablets to check underground utilities and projected completion models as they work.

Simple Surveying with LRTK

Finally, as a new tool to easily realize AR visualization on site, we introduce LRTK. LRTK is a solution that combines a compact high-precision GNSS receiver with a smartphone to enable simple high-precision positioning on site. By using a dedicated ultra-compact RTK-GNSS device (for example, an “LRTK Phone” that can be attached to the back of a smartphone), an ordinary smartphone instantly becomes a surveying device with centimeter-level accuracy and an AR terminal. Without complicated base station settings or marker installation, simply powering on the device automatically acquires high-precision self-positioning and accurately projects 3D design data into the real world.

With this simple surveying system, even non-surveying specialists can intuitively use AR technology. For example, a single technician walking around a site with a smartphone can handle everything on the spot—from checking the positions of buried utilities and guiding pile-driving positions to checking as-built conditions and taking photo records. Survey results and site photos can be shared to the cloud immediately, reducing the time needed to return to the office to prepare drawings. High-precision AR enabled by LRTK directly contributes to reduced construction errors and more efficient surveying, improving overall site productivity. Because accurate as-built data can be shared with clients in real time, the consensus-building described earlier becomes much smoother.

Thus, LRTK plays a major role in lowering the barrier to AR visualization adoption by making “high-precision AR anyone can use right away” possible. Even sites that hesitated because equipment seemed expensive or operation difficult can easily try AR using LRTK. Embrace the latest technologies and achieve safe, efficient smart construction.

FAQ

Q: What is needed to perform AR visualization of underground utilities on site? A: The basics are digital data that include accurate position information of utilities (e.g., utility drawings or 3D models) and AR-capable devices that can display them on site. First, survey the locations of utilities in advance and convert them to 3D data, then load them into an AR app on a tablet or smartphone. To accurately align the device, use high-precision GPS (GNSS) or RTK base stations, and, where needed, correction services via the Internet. In short, AR visualization is possible only when both “data that show what is where underground” and “positioning technology to overlay that data without offset on site” are in place.

Q: Will AR really make underground utilities “visible”? A: Yes—on the device screen they will appear as if actually visible. AR overlays virtual imagery on the real world; it does not literally see through the ground. However, if you have accurate position and shape data for utilities, you can render them aligned with the real scene to create the visual effect of seeing through the ground. For example, if a water pipe is buried 1 m (3.3 ft) below the ground in front of you, the AR app will display a CG model of the pipe at the corresponding location on screen. As a result, the pipe appears to float under the ground when viewed through the device.

Q: Can AR be used indoors or in places where GNSS is unavailable? A: Yes, there are methods to use AR where GNSS (GPS) cannot reach, though it is more complicated than outdoors and requires some ingenuity. For indoor or tunnel environments, techniques such as camera-based SLAM to estimate device position or alignment using markers placed on ceilings or walls are used. Some large construction firms’ underground utility visualization systems combine proprietary SLAM functions for cases where GNSS signals are not available. However, accuracy tends to be lower than outdoors in such cases, so operation must be more cautious. In dense urban areas where GPS accuracy is unstable, countermeasures such as temporary base stations or matching with known control points around the site are applied on a case-by-case basis.

Q: Do I need specialized skills to operate AR? A: Previously, operation required advanced equipment handling and 3D software knowledge, but recent AR systems are quite user-friendly. Basic operations are often intuitive—tapping a tablet screen or holding up the device—so site workers can learn them with short training. However, data preparation (3D modeling of drawings and coordinate alignment) does require some knowledge, so it is advisable to have an IT-savvy person support initial setup. Tools like LRTK, which simplify equipment setup, make it possible for non-specialists to use high-precision AR effectively.

Q: What kinds of construction sites are suitable for AR visualization of utilities? A: AR is effective for any project involving underground utilities, but it is particularly useful in urban roadworks, piping works, and infrastructure maintenance. On sites with many underground lifelines, AR’s ability to present spatial relationships in three dimensions offers major safety benefits. It is also valuable for work where the relationship to underground structures is critical—such as trench excavation or pier foundation work. In addition, AR is powerful for cases where stakeholders want to preview the completed appearance or layout—for example, public works requiring landscape considerations or community briefings. In short, AR visualization of utilities delivers its greatest value on sites where “sharing invisible information” is necessary or where “precision is essential” and mistakes cannot be tolerated.