AR civil engineering is powerful for explaining to local residents! Building consensus by sharing the completed image

Table of Contents

• What is AR civil engineering?

• Clarity required when explaining to local residents

• Benefits of sharing completed images using AR

• Examples of AR use in explanations to local residents

• Technical elements supporting high-precision AR display

• Making AR technology accessible to everyone: simplified surveying with LRTK

• FAQ

What is AR civil engineering?

In recent years, the use of AR technology on construction and civil engineering sites has been rapidly advancing. "AR civil engineering" is a coined term referring to initiatives that utilize AR (augmented reality) in the civil engineering field. AR technology, which can overlay design drawings and 3D models onto real-world scenery through a smartphone or tablet camera, can be described as a tool that bridges the field and digital information. Because it can display the completed appearance of infrastructure in true scale on-site—information that used to be confirmed only via drawings or artist impressions—it is highly intuitive and easy to understand not only for project personnel but also for local residents.

For example, the completed look of a not-yet-built bridge or a road widening can be displayed over the planned construction site through a smartphone. Because one can confirm in real time how a future structure will rise within the actual scenery, spatial impressions that were hard to grasp from drawings alone become immediately clear. This realization of “seeing is believing” through AR civil engineering technologies is beginning to demonstrate effectiveness across a wide range of areas, including consensus building, construction management, and education and training.

Clarity required when explaining to local residents

When undertaking civil engineering works, it is essential to explain the project plan and the completed image to local residents in advance to gain their understanding and cooperation. However, traditional explanation methods have several issues. Paper drawings, plan views, and artist impressions alone make it difficult for laypeople without technical knowledge to concretely imagine the post-completion appearance. Especially in large-scale structures or works that affect the landscape, it can be hard to grasp “what it will actually look like when finished,” which can lead to anxiety or opposition. For example, concerns such as “Will this structure affect sunlight?” or “Will it spoil the scenery?” are difficult to dispel with drawings alone.

Even when models or perspective drawings are provided, different viewers may interpret them differently, leading to mismatches such as “It’s different from what I expected” or “The real thing differs from the image I was shown,” which can later become trouble. Such insufficient explanations and gaps in understanding can hinder local acceptance of a project and, in some cases, cause construction delays or additional costs. Therefore, when explaining to local residents, it is extremely important both to convey information in a way everyone can understand and to ensure a shared image among stakeholders.

Benefits of sharing completed images using AR

An emerging means to solve these issues is sharing completed images using AR technology. With AR civil engineering technology, a 3D model of the planned structure can be overlaid on-site and presented on the spot, allowing all stakeholders, including local residents, to share the same image of the finished project. This greatly reduces gaps in understanding and dramatically improves the speed and accuracy of consensus building.

For example, at a residents’ briefing for a road or bridge project, if you use a tablet’s AR function to show an overlaid completion image on site, participants can intuitively understand what kind of structure will appear within the actual landscape, making it clear to everyone “this is going to be built here.” As a result, the “seeing is believing” effect helps ease anxiety and opposition, making it easier to obtain residents’ agreement. There are actual cases where using AR in resident briefings led to smoother consensus building, and the ability to instantly share information that was hard to convey with drawings or words alone is highly significant.

Moreover, if the completed image is shared via AR on site, it becomes easier to elicit specific questions and opinions from residents. If concerns like “Will this height block my view?” arise while watching the AR visualization, the project staff can immediately explain or consider design adjustments. Conducting visual confirmation and discussions in advance prevents misunderstandings of “this wasn’t what I expected,” reducing later plan changes and complaints. In other words, clear explanations using AR help build trust with residents and prevent trouble, which in turn suppresses schedule delays and unnecessary cost increases and contributes to smoother project progress.

Examples of AR use in explanations to local residents

The effectiveness of AR civil engineering has already been demonstrated at several sites. For example, in a municipal intersection improvement project, the construction team used AR-capable head-mounted displays and positioning systems to accurately project the positions and shapes of future roads and gutters at the site during the construction phase. As a result, even in a road widening project extending over 200 m (656.2 ft), virtual models could be displayed at full scale with accuracy on the order of just a few millimeters, which greatly aided explanations of the completed form to local residents. Residents commented, “I felt reassured because I could clearly imagine the finished appearance,” and “I was convinced because I could check parts that were unclear in the drawings on site,” and negotiations over design changes that used to drag on were completed in a short time, markedly streamlining the consensus-building process.

In another case, a bridge construction project held an on-site tour using AR models. Local residents who participated used dedicated tablets to experience how the completed bridge model blended into the river scenery, receiving high praise such as “Being able to experience the final form on the spot made it very easy to understand.” By using AR, the post-completion appearance of large structures that were previously hard to imagine can be conveyed intuitively, which smooths communication at resident briefings and site tours and helps prevent unnecessary misunderstandings or conflicts.

Furthermore, AR is effective even for small-scale works and familiar infrastructure improvements. For example, at the municipal level for road repairs or park development, sharing the completed image via AR before construction can make resident briefings smoother and help gain understanding and cooperation for the work. Municipalities with limited budgets and personnel can particularly benefit from the efficiency gains of simple AR technology. On small sites where a supervisor may cover multiple roles, being able to compare design drawings and current conditions on a tablet AR screen helps reduce human error. Regardless of scale, the benefit of AR—“being able to confirm intuitively on site”—is commonly useful, and such use cases are expected to increase.

Technical elements supporting high-precision AR display

Several technical elements are required to overlay 3D models onto the site with AR. First and foremost are the devices and AR apps. Modern smartphones and tablets have become remarkably high-performance; the latest iPhones and iPads are equipped with LiDAR sensors. Using LiDAR, the surrounding terrain and structures can be scanned at high speed as point cloud data, allowing the real shape of the environment to be incorporated into the AR space so that virtual models sit naturally on the ground and achieve realistic occlusion where virtual objects are hidden behind real ones. Also, platforms such as Apple’s ARKit and Android’s ARCore employ camera and sensor-based VIO (Visual-Inertial Odometry) technology to track device position and orientation. This allows virtual objects to remain fixed in place even as users walk around.

However, because ordinary smartphone GPS can have errors of several meters, attempting to place AR displays of large structures accurately across wide civil engineering sites previously led to gradual drifting of model positions. While placing markers for alignment is an option, it is labor-intensive to show the overall completed image of a site. An approach that has attracted attention recently is absolute coordinate AR using high-precision GNSS. By placing AR models based on absolute coordinates—latitude, longitude, and height—obtained via satellite positioning (GNSS), model placement can be aligned precisely with actual survey coordinates. This enables accurate overlay of completed models in AR even for infrastructure works spanning tens of meters or more.

Moreover, combining multiple state-of-the-art technologies has made on-site AR use more practical. For example, using a compact RTK-GNSS receiver that attaches to a smartphone enables centimeter-level high-precision positioning with a palm-sized device. Based on the acquired coordinate data, 3D models can be displayed on site at high accuracy immediately, so tasks that used to require specialized surveying instruments and experienced technicians can now be completed in a short time. In addition, systems for sharing point cloud data and photos captured on site via the cloud are becoming available, allowing office staff to grasp construction status remotely or give instructions and confirmations through AR displays. The fusion of these technical elements is evolving AR civil engineering into something more familiar and easier to use for everyone.

Making AR technology accessible to everyone: simplified surveying with LRTK

A key to utilizing high-precision AR displays on site is the aforementioned positioning using RTK-GNSS. However, traditional RTK surveying has been high-barrier: it often required total stations or expensive GPS surveying instruments, or two-person teams of survey technicians with specialized knowledge. Enter new simplified surveying solutions typified by LRTK. LRTK is an all-in-one high-precision positioning and AR system that combines a compact RTK-GNSS device attachable to a smartphone, a dedicated app, and a cloud service. With a single smartphone you can perform centimeter-level positioning, 3D scanning, and AR model overlay in an integrated workflow, allowing tasks that previously relied on specialized equipment and experienced personnel to be handled by anyone intuitively.

For example, by attaching an LRTK receiver to an iPhone and launching the app, you can obtain positioning accuracy of several centimeters with just button operations and without complex procedures. The acquired point clouds and coordinate data are automatically saved to the cloud, making sharing a one-tap action. In other words, introducing simplified surveying with LRTK greatly streamlines the complicated on-site procedures for positioning and model placement. This lowers the barrier to accurate AR overlays based on absolute coordinates, making it increasingly possible for non-experts such as municipal staff and construction managers to use AR themselves.

Going forward, initiatives such as *i-Construction* promoted by the Ministry of Land, Infrastructure, Transport and Tourism and the trend toward on-site DX will provide tailwinds, and smartphone-based AR surveying technologies like these are expected to spread further. In practice, some municipalities have introduced iPhone-based surveying and AR systems in disaster recovery sites, significantly reducing work time and costs. AR civil engineering is becoming a new standard for gaining public understanding and cooperation through on-site visualization. By leveraging technologies like LRTK, we can create an environment in which local residents and project teams share the same image and advance projects with faster and more reliable consensus building.

FAQ

Q: What is AR civil engineering? How is it different from VR or CG? A: AR civil engineering is a general term for initiatives that utilize augmented reality (AR) technology in the civil engineering field. It overlays 3D models and drawing information onto real space via a smartphone or tablet screen, allowing users to intuitively check completion images and construction status on site. VR (virtual reality) is entirely within a computer-generated virtual space, whereas AR augments the real scenery with virtual information. In other words, VR is an experience of a “completely virtual world,” while AR is an “enhancement of the real world.” In civil engineering, AR is better suited than VR for resident briefings and on-site construction use because it allows verification and explanation while viewing the actual site.

Q: Is AR-based explanation effective for elderly people or those not familiar with devices? A: Yes. AR explanations are effective even for people without technical knowledge. Because viewers can understand intuitively by simply “looking” at the image on a smartphone or tablet screen, elderly people tend to feel less resistance and may even enjoy the experience while gaining understanding. There is no need to decipher complicated drawings; because the predicted completion is composited into the actual scenery, people can sensually grasp “this is what will be built here.” If the presenter operates the device to show the view, the audience can understand it in much the same way they normally watch TV, making it an accessible method for everyone.

Q: Does introducing AR technology require high costs? A: You can use AR on handheld smartphones and tablets without preparing special head-mounted displays, so the cost of introduction has dropped significantly compared to the past. If higher-precision GNSS receivers are required, add-on purchase may be necessary, but compact and relatively inexpensive devices are now available, making it possible to introduce AR at lower cost than traditional surveying instruments. In many cases, an AR environment can be built by retrofitting existing mobile devices, so site introduction can be achieved without large-scale investment.

Q: What equipment and preparations are needed for AR display? A: Basically, you can get started with an AR-capable smartphone or tablet. Recent iPhones and iPads are equipped with AR functions and LiDAR sensors, enabling high-precision AR. For more precise alignment, an RTK-GNSS–compatible compact receiver is ideal. Lightweight RTK receivers that attach to smartphones are commercially available, and used together they can provide centimeter-level positioning. You will also need 3D model data and a dedicated app capable of AR display. Recently, systems that manage model data in the cloud and can call them up on site have become available, so if you prepare model data in advance you can perform AR display immediately at the site.

Q: Can AR positioning be performed indoors or inside tunnels where GNSS cannot be used? A: In environments where GNSS signals cannot reach, centimeter-level positioning via RTK is not possible. However, certain countermeasures are feasible. For example, you can perform high-precision alignment outdoors near the tunnel entrance to establish reference points, and inside the tunnel maintain the display using the smartphone’s relative AR tracking. Another approach is to survey the coordinates of reference points inside the tunnel in advance and place markers so the AR model can be aligned to those markers. While it is difficult to achieve high precision over wide areas without GNSS, for limited ranges you can secure a certain level of accuracy by using surrounding landmarks or visual markers.

Q: Is AR-based resident explanation effective for small-scale municipal works? A: Yes. In fact, small-scale projects—where resources for preparing materials and explanations are limited—stand to gain the most efficiency benefits from AR. With simple operations you can project the completed image on site, reducing the preparation burden for resident briefings and making it easier to obtain understanding. Even for road repairs or small park improvements, sharing the completed image via AR beforehand can prevent gaps such as “it turned out different from the image.” AR is applicable regardless of the project scale, so municipalities should consider actively adopting it regardless of budget size.

Q: What is LRTK? How does it differ from conventional surveying instruments? A: LRTK is a high-precision positioning and AR solution that integrates a compact RTK-GNSS receiver, a smartphone app, and cloud services. Unlike conventional instruments such as total stations that required specialized qualifications or experience, LRTK allows anyone to carry out centimeter-level surveying and point cloud scanning simply by attaching the device to a smartphone and operating the app. Acquired data is stored in the cloud and can be shared among multiple users for real-time use. In short, LRTK enables one-stop workflow from positioning to AR display, making on-site AR utilization possible without special equipment or advanced skills.