Challenges and Countermeasures for Introducing AR in Civil Engineering: Key Points to Ensure Success

Table of Contents

• What is AR technology? The wave of digitalization spreading through the civil engineering industry

• Benefits of introducing AR

• Challenges of introducing AR in civil engineering

• Countermeasures and success points for introducing AR in civil engineering

• Using LRTK to achieve simple AR-based surveying

• FAQ

In recent years, the use of AR (Augmented Reality) technology on construction and civil engineering sites has been attracting attention. AR, which can overlay design data and construction information on real-world images simply by pointing a smartphone or tablet, allows completion images that were previously only visible on drawings or 3D models on a computer to be intuitively understood on the spot. As a result, many benefits are expected, such as reduction of construction errors, smoother consensus-building among stakeholders, and improved work efficiency. In fact, attempts to project 3D models onto sites can be used broadly, from pre-construction simulation to verification of as-built conditions, and interest is growing across a wide range of players—from large general contractors to small and medium-sized contractors, clients, and local governments.

However, there are challenges to overcome when fully introducing AR technology on sites. For example, issues around devices and positioning accuracy, the proficiency of site staff and operational methods, and introduction costs are some of the points that need to be addressed. This article first briefly clarifies what AR is and explains the benefits of introducing AR in civil engineering. It then concretely introduces common challenges faced when introducing AR and countermeasures for them, and examines key points to ensure the successful introduction of AR in civil engineering. Finally, using the latest simple surveying solution LRTK as an example, it discusses ways to solve these challenges and make AR easy to use on site.

What is AR technology? The wave of digitalization spreading through the civil engineering industry

AR (Augmented Reality) is a technology that overlays computer-generated information on images of the real world. Technically, it composites 3D CG models and text information in real time onto the real scenery captured through the cameras of smartphones, tablets, or smart glasses. This enables the display of objects or explanations that do not actually exist in the space before you, allowing you to check drawings and models on site.

In the civil engineering and construction industries, there have long been many situations where reading drawings and presenting completion images is challenging. Two-dimensional drawings make it difficult to share post-completion images, and differences in stakeholders’ images can cause rework. AR technology can, for example, overlay the completed image of a road or bridge onto the actual scenery or visualize the location of buried pipes through the ground. When the real object and the projected completion image match in real time, on-site meetings become smoother and miscommunication of design intent can be reduced.

Also, initiatives such as *i-Construction* promoted by the Ministry of Land, Infrastructure, Transport and Tourism are accelerating the digitalization of construction sites (so-called site DX). As the use of 3D data such as BIM/CIM becomes widespread, the introduction of AR on sites as a natural extension is likely to expand further. In fact, recently, on-site support tools using tablets and smart glasses have begun to be offered by various companies, and AR technology is contributing significantly to the wave of digitalization in the civil engineering field.

Benefits of introducing AR

Major benefits of introducing AR on civil engineering sites include the following:

• Facilitating consensus-building through visualization: AR can smoothly facilitate consensus with clients and nearby residents by overlaying completion images that are difficult to convey with drawings or specifications onto the actual scenery. For example, in bridge construction, AR displays of the projected bridge at the site help stakeholders intuitively understand scale and visual impact.

• Reduction of construction errors and rework: AR can prevent construction errors caused by overlooking or misreading drawings. By aligning and checking the design model displayed in AR with the actual position on site, mistakes in dimensions or placement can be detected early. In rebar (reinforcement) inspections, overlaying the design model’s rebar in AR and comparing it with the actual installation allows on-the-spot identification of errors in number or spacing. Such checks reduce later rework and contribute to quality assurance.

• Improved work efficiency: Surveying, inspection, and recording tasks can be streamlined. For example, in as-built inspections, instead of surveying and creating drawings for later comparison, you can immediately compare the design model and the as-built on site by overlaying them with AR. Simply pointing a smartphone or tablet lets you compare design and construction results, greatly shortening the time required for inspection reporting. In addition, AR information can be recorded as photos or videos and attached directly to reports, becoming persuasive evidence.

• Support for heavy equipment operation and improved safety: AR helps not only human workers but also heavy equipment operation. If the locations of buried objects are displayed in AR during excavation, operators of excavators (backhoes) can visually recognize prohibited digging zones. Marking hazardous areas or no-entry zones in AR also alerts site workers and contributes to safety management.

• Training and knowledge sharing: AR is useful as an educational tool for young engineers. Using AR-guided displays on actual sites makes veteran know-how visible and transferable to newcomers. For example, overlaying construction procedures or inspection points on site images enhances OJT (on-the-job training) effectiveness. Remote experts can also share AR images and give real-time advice, enabling remote support.

Thus, AR introduction is expected to bring various benefits such as improved communication, better quality and safety, and increased operational efficiency. On the other hand, several hurdles remain to actual on-site utilization. Next, we will look at challenges commonly faced when incorporating AR technology into civil engineering sites.

Challenges of introducing AR in civil engineering

Even innovative AR technology has issues that must be solved to use it effectively on site. Major challenges include the following points:

• Positioning accuracy and environmental factors: Accurate positioning technology is essential to align design data correctly in AR. However, general smartphone GPS has errors of several meters (several ft), which is insufficient for civil engineering works involving large structures. Satellite signals can be blocked or become unstable under elevated structures, in urban canyons, or in wooded areas. Around metal structures, signal reflections (multipath) can also cause significant errors. Ensuring AR accuracy in such environments requires matching with known points (control points) or combining auxiliary positioning means (total stations, local beacons, etc.), which is a challenge.

• Device display quality and operability: Smartphones and tablets, which are currently central to AR use, present specific issues for outdoor use. For example, screens are hard to see in direct sunlight, and devices may overheat and become unstable in midsummer heat. Although water- and dust-resistance have improved over the years, durability for construction sites still raises concerns. Measures such as using rugged cases and carrying spare batteries are advisable. Also, holding a device by hand for long periods is burdensome, so using a monopod (single-leg tripod) or a helmet-mounted holder, and in the future considering head-mounted AR glasses, are measures to consider.

• 3D data preparation and compatibility: Preparing 3D model data for AR display takes effort. CAD or BIM data must be exported and converted into formats readable by AR apps. Very detailed large models can be heavy for mobile devices, so simplification and LOD (level of detail) adjustments may be necessary. In addition, tasks such as aligning Japan’s surveying coordinate systems (plane rectangular coordinates or the World Geodetic System) with the AR app’s coordinate system occur, requiring cross-system compatibility work. If this initial preparation is complicated, it hinders on-site adoption, so simplifying and automating these steps is a challenge.

• Staff proficiency and operational rules: Human adaptation is also needed to use AR tools on site. While many apps are intuitive and easy to operate, site staff may still need a training period to utilize them fully. Long-experienced veterans may resist changing traditional methods. Also important is establishing operational rules about how much to rely on AR-displayed information and whether conventional measurements should accompany final verification. Without agreements such as “AR information is a reference and final checks are performed by people,” confusion may arise between what is technically possible and existing site practices.

• Introduction costs and verification of effectiveness: Cost is a common challenge with new technology. Initial investment in dedicated AR hardware and software, costs of 3D data creation and outsourcing, and other expenses occur at introduction. Large projects can more easily justify the investment, but for small-scale works it is necessary to carefully assess whether benefits justify costs. Training costs for staff should also be considered. If cost-effectiveness is unclear, AR may be dismissed as an “expensive toy,” hindering on-site penetration.

As described above, introducing AR into civil engineering involves technical and operational barriers. However, various countermeasures and technology advances have already produced solutions to these challenges. The next section presents countermeasures for AR introduction based on the issues above and points to lead to success.

Countermeasures and success points for introducing AR in civil engineering

Key countermeasures and points to ensure the successful introduction of AR in response to the challenges mentioned are as follows:

• Use high-precision positioning technologies and backup measures: To address positioning accuracy issues, leveraging high-precision GNSS positioning (such as RTK) is effective. Connecting a compact dedicated GNSS receiver to a smartphone or tablet and using base station or correction information can reduce positioning errors to the order of a few centimeters (a few in), enabling accurate alignment of design models even on large sites. In environments where satellites are hard to receive, such as under elevated structures, having backup measures like checking against known points or using local positioning systems is reassuring.

• Prepare site-appropriate devices and peripherals: Device issues can be managed by site-oriented adaptations. Use sunshades (screen hoods) to mitigate glare, and operate devices so they can rest during hot seasons to prevent overheating. Rugged protective cases and portable power supplies are basics. To address the problem of one hand being occupied, fix devices on a monopod or use helmet-mounted holders. In the future, goggles-type AR glasses will allow hands-free operation, so for now use tablets plus accessories while monitoring new device trends.

• Organize data integration and simple operational workflows: Simplify 3D model preparation by standardizing user-friendly tools and formats. If BIM/CIM is used from the design stage, design data can be readily converted for AR use. Prepare internal standard procedures for 3D data creation and build libraries of frequently used components and terrain models. Also, coordinate integration between in-house systems or surveying equipment and AR apps to eliminate coordinate shifts. Recently, AR solutions that support surveying coordinate systems have appeared and can automate complex coordinate alignment tasks. Utilize such systems to enable site staff to use AR with minimal hassle.

• Phased introduction and human resource development: Address human barriers with phased introduction and careful training. Start with pilot implementations on small sites or projects to verify effectiveness and usability internally. Have key young staff become proficient first and demonstrate on site to reassure veteran staff. Holding workshops and hands-on sessions to let people experience AR’s usefulness is effective. For operational rules, discuss with stakeholders on each site to decide which tasks AR will handle and which require human verification to prevent confusion. Accumulate success cases gradually and build in-house know-how so the mindset “using it is easier and more reliable” spreads, which accelerates adoption.

• Clarify ROI and select appropriate tools: To address cost concerns, clarifying ROI (return on investment) is essential. Quantitatively show how AR leads to shorter schedules and fewer errors, resulting in cost savings and higher profits. If initial costs are a concern, avoid insisting on expensive dedicated devices; instead use affordable AR apps that run on existing smartphones or tablets, or small add-on devices. Subscription-based services that can be used on demand are also becoming available, reducing upfront investment. Choose tools that fit your company size and projects, and start with partial implementation to measure effects. Demonstrating success with numbers increases credibility with management and clients and encourages further investment and broader use.

By implementing these measures, the barriers to AR introduction can be steadily lowered. Technology is advancing rapidly, making devices easier to handle and enhancing precision and automation. As the construction industry steers toward DX, effectively incorporating AR can differentiate companies and showcase technical capability. Next, we introduce LRTK for simple AR surveying as one of the latest solutions that addresses these challenges.

Using LRTK to achieve simple AR-based surveying

One solution attracting attention for making AR easy to use on site is “LRTK.” LRTK is a next-generation positioning system developed by Reflexia Inc., consisting of a small RTK-GNSS receiver that can be attached to a smartphone, a dedicated app, and cloud services. Using LRTK, an ordinary smartphone can quickly transform into a surveying instrument with centimeter-level precision (half-inch accuracy). It is an integrated tool that handles on-site measurement and recording tasks in one device, from position measurement to photo recording, 3D point cloud scanning, and projection of 3D models in AR.

A major feature of LRTK is that you can use high-precision AR with a single switch without cumbersome on-site alignment (calibration). Thanks to a high-performance GNSS antenna and real-time correction technology, the device’s position can be accurately captured in a global coordinate system, enabling automatic overlay of BIM/CIM models with pre-existing coordinate information at their design positions. For example, by approaching the planned pier location, the bridge pier’s completion model can appear in AR rising from empty ground. Tasks that formerly required placing and scanning QR code markers on the ground or manually adjusting model positions to known points become unnecessary with LRTK. Simply bringing the device to the site and powering it on enables high-precision AR simulation and surveying on the spot, making it easy for anyone to use.

LRTK also integrates with cloud services and automatically saves and shares recorded photos and point cloud data. Multiple devices can synchronize position information and AR displays in real time, enabling collaborative work where the site and the office—or remote locations—share the same AR space. By leveraging such state-of-the-art tools, the aforementioned challenges to AR introduction can be addressed comprehensively, accelerating DX in civil engineering sites.

FAQ

Q. What is the difference between AR and VR? A. AR (Augmented Reality) overlays digital information onto the real scenery. VR (Virtual Reality) immerses the user in a fully computer-generated virtual environment. AR supplements and extends the real world, whereas VR is used for experiences separated from reality. On construction sites, AR—which overlays design models onto the real scenery—is better suited for direct work support and consensus-building.

Q. What is needed to use AR on civil engineering sites? A. Fundamentally, you need a device with a camera and display (a smartphone, tablet, or dedicated AR glasses) and an application for AR display. Additionally, to overlay design data accurately, it is desirable to have 3D design models (BIM/CIM data) and positioning equipment. For higher positioning accuracy, using an RTK-GNSS-capable receiver enables AR displays with less offset. Recently, small GNSS units that attach to smartphones and devices that can perform simple 3D scanning have appeared, making AR usable without large special equipment.

Q. How accurate are surveying and measurement results obtained with AR? A. Standalone smartphones typically have positioning accuracy on the order of several meters (several ft), but combining them with high-precision positioning such as RTK-GNSS can improve accuracy to the order of a few centimeters (a few in). For elevation, built-in tilt sensor corrections combined with high-precision positioning can, in some cases, measure elevation from the ground surface with errors within a few centimeters (a few in). However, where millimeter-level precision is required, verification with conventional optical surveying instruments may still be necessary. AR surveying is primarily a complementary method that excels in immediacy and convenience, but it has reached a level sufficient for common civil construction management accuracy requirements.

Q. Can small-scale contractors and small-to-medium enterprises also introduce AR technology? A. Yes, it is quite possible. Recent AR solutions increasingly work on existing smartphones and tablets without expensive dedicated equipment. Cloud-service models can reduce initial costs, and subscription-based services that allow monthly use when needed are emerging. Start small with staff knowledgeable in ICT, evaluate effects, and expand gradually. AR is applicable not only to large-scale projects but also to small site safety checks and as-built verification across various scales.

Q. Is in-house training or instruction necessary for AR introduction? A. As with any new tool, it is advisable to conduct training on basic operation and use cases. However, many modern AR apps are intuitive, and people familiar with smartphones and tablets can often use them after a short explanation. The important thing is to provide opportunities to actually use AR on site. Using AR in site tours or trial constructions and building experience reduces staff resistance. Sharing success stories from early adopter sites within the company and communicating benefits and tips is also effective. Through these efforts, making AR use the new site “normal” is the ideal outcome.