Railway Signal and Communication DX Frontline: Improving Work Efficiency and Reducing Costs with Point Cloud Scanning

Railway signaling equipment and communication infrastructure across Japan are aging, and the aging and shortage of technicians who support them is becoming increasingly severe. While the need for equipment renewal and maintenance to ensure safe transportation is rising, the burden on field operations continues to grow due to work time constraints and staff shortages. For example, inspections and works on trackside signals and cables are often carried out during the limited nighttime window from the last train to the first train to avoid impacting train operations, requiring precise work to be completed in a short time. Moreover, maintaining a wide range of railway infrastructure (signals, level crossing equipment, communication cables, etc.) demands considerable effort, and relying on traditional manual methods presents a major efficiency challenge.

Against this backdrop, the railway industry is strongly demanding on-site digital transformation (DX) to innovate field operations. In recent years, infrastructure inspection and automation technologies utilizing 3D scanners, AI, and IoT have attracted attention. This article introduces how a new solution combining point cloud scanning (3D laser scanning), high-accuracy positioning, and AR (augmented reality) can realize work efficiency improvements and cost reductions in the railway signal and communication infrastructure domain. From field challenges to concrete use cases, we will look at the latest DX initiatives.

Challenges Facing Railway Signal and Communication Infrastructure Worksites

First, let’s organize the current challenges faced in the design, construction, and maintenance of railway signal and communication infrastructure (signal heads and poles, level crossing control devices, trackside communication cables and ducts, etc.).

• Responding to aging equipment and design burden: When renewing aging signal equipment or planning new installations, detailed on-site understanding is required. Traditionally, engineers would go to the site and survey, using drawings and scales to determine positions. However, during nighttime work or in the brief gaps when train radios are off, there is often insufficient time to measure conditions adequately. It is also difficult in the design phase to accurately grasp positional and height relationships with surrounding structures, and paper drawings or two-dimensional materials often leave many aspects to intuition and experience.

• Positioning work during construction and labor shortage: During the construction phase for installing signal poles and communication equipment, accurately marking installation locations on site based on drawings—“positioning for installation”—is indispensable. Typically, this stake-driving and positioning work is carried out by two surveying specialists using total stations or carefully progressing with surveying instruments and marking work. However, chronic staff shortages mean experienced surveyors may not be available, and the burden of transporting heavy surveying equipment reduces work efficiency. On-site, with time pressure, the load of accurately marking positions with limited personnel is significant, and safety must also be considered.

• Maintenance and difficulty understanding buried utilities: There are also challenges in post-installation maintenance. The exact positions of buried communication ducts (conduits for cables) and wiring routes often rely on drawings and records from the time of construction, but over time these can become outdated and inaccurate, leaving sites in a state of “not knowing what is buried where.” When excavating for new work there is a risk of damaging existing cables, so it is important to reliably identify the positions of buried objects in advance. Additionally, when equipment conditions are understood based on the knowledge and experience of veteran workers, the issue of difficulties in passing on know-how arises with generational change.

• Inefficient information sharing and rework: Poor information sharing of construction plans and on-site conditions also hinders field DX. Even if designers determine the best layout on CAD drawings, it is not easy for on-site workers to visualize it. Conversely, when problems occur in the field (for example, the presence of an obstacle), conveying the situation to headquarters or designers with only drawings and photos can fail to accurately represent the conditions, causing misalignment of understanding among stakeholders. As a result, rework such as “it’s different from the design” or “it’s off from the expected location” can occur after construction, leading to increased man-hours and costs.

As described above, railway signal and communication infrastructure worksites face complex challenges including the burden of precise surveying, constraints from nighttime work, shortage of skilled workers, and insufficient information sharing. To solve these and improve efficiency, digitizing and smartening on-site work is an effective approach. The key to this is the solution using point cloud scanning × high-precision positioning × AR, introduced next.

Point Cloud Scanning × High-Precision Positioning × AR: The LRTK Solution

In light of the challenges above, LRTK is expected to be a trump card for on-site DX. LRTK (L-R-T-K) is a solution that realizes “centimeter-level high-precision positioning,” “3D point cloud scanning,” and “AR display (augmented reality)” with a single smartphone. By combining a dedicated compact high-precision GNSS receiver with an app, surveying and 3D measurement that previously required specialized equipment can be easily performed. In other words, it is a groundbreaking tool that turns a smartphone into an all-purpose surveying device, offering many benefits in the railway signal and communication infrastructure field.

The main features and functions of LRTK are as follows:

• Centimeter-level high-precision positioning: Ordinary GPS positioning has errors of several meters, but LRTK uses RTK technology (real-time kinematic) to determine the current position with very high precision—about 1–2 cm horizontally and about 3 cm vertically. This makes it possible to accurately acquire and specify the coordinates of signal pole installation positions and buried cables in a map coordinate system. Positioning is completed with just a smartphone and a pocket-sized receiver, eliminating the need for heavy tripods or large equipment. Because it can be carried and surveyed by one person, it enables rapid positioning and measurement work even at sites with staff shortages.

• On-site digitization through 3D point cloud scanning: Using the LiDAR sensor (laser distance measurement) and camera built into a smartphone, site conditions can be recorded directly as three-dimensional point cloud data. For example, simply walking a few minutes along the trackside can scan terrain and existing structures (bridge piers, sign locations, etc.) and acquire high-precision 3D data of millions of points. Acquired point cloud data are georeferenced (latitude, longitude, elevation), allowing precise overlay with drawings and maps. This point cloud scanning creates a digital copy of the site, enabling designers to perform precise measurements and reviews from the office. This can reduce nighttime on-site surveys and help identify interference points that paper drawings might miss.

• AR display to visualize design data on site: LRTK includes AR functionality that can overlay design drawings and 3D models on the real scenery through the smartphone screen. Thanks to high-precision positioning, there is no misalignment in registration, so models appear on-site where they are supposed to be according to the drawings. This allows, for example, placing a virtual signal pole at a planned installation point to check relationships with surroundings and sightlines, or displaying buried cable routes from above ground to check for conflicts with obstacles. AR displays are intuitive and easy to understand, benefiting not only field workers but also clients and stakeholders. Instead of mentally visualizing a 3D image from drawings, AR enables sharing a life-size completed image.

• Cloud integration and data sharing: Point cloud data, coordinate information, photos, and other records captured with LRTK can be uploaded to the cloud and shared among stakeholders. Even those without proprietary software can view and measure 3D point clouds via a web browser, enabling real-time sharing of detailed on-site information with office designers and other departments. This makes conveying on-site conditions dramatically easier, reducing communication loss between design and construction. Storing data in the cloud also allows reusing past as-built data for future maintenance planning or other projects, preventing redundant surveys.

Through these functions, LRTK digitizes surveying, measurement, and information sharing on site end-to-end. The ease of use without heavy machinery or specialized surveying equipment is a major advantage for railway construction sites. The next chapter looks at concrete scenes where LRTK can be used in railway signal and communication infrastructure operations.

LRTK Use Cases in Railway Signal and Communication Infrastructure

Given LRTK’s features, there are many use cases in the railway signal and communication fields. Here, we present three representative examples—“positioning for signal pole installation,” “identifying underground communication ducts,” and “information sharing with the field”—and describe their effects.

Use in Positioning for Signal Pole Installation

When constructing new railway signal poles or renewing aging signals, poles must be installed precisely at positions specified in design drawings. LRTK significantly contributes to the efficiency of positioning work (stake driving).

Traditionally, survey teams would go to the site, measure distances and angles from reference points, and mark locations. With LRTK, you can load coordinate data for signal poles obtained from design drawings into a smartphone via the cloud in advance and then simply display those points in AR on site to immediately identify installation positions. Virtual poles or markers appear on the smartphone screen, so workers can intuitively understand where to dig on the actual ground. Using LRTK’s coordinate guidance function, the smartphone guides you like a navigation device to the target coordinates, enabling accurate stake driving even without experienced personnel.

Post-installation verification is also easy. Overlaying a pole model in AR allows immediate checking for any misalignment, and if everything is correct you can 3D-scan the as-built state for records. Later, reporting to clients or internally that the pole was installed “in accordance with the design” with supporting 3D data or AR images provides persuasive evidence. Introducing LRTK shortens the time required for positioning work and brings secondary benefits such as smooth information sharing with stakeholders and simplified deliverable reporting.

Grasping and Visualizing Underground Communication Ducts

Cables for signal control and inter-station communication are buried along railway lines. LRTK is powerful for accurately identifying underground communication ducts.

For example, when relocating communication cables in a section, it is first necessary to confirm the positions of existing buried ducts. With LRTK, when a trial excavation exposes an underground cable duct, you can perform a 3D point cloud scan of the surrounding area to record the duct’s precise route. Because the acquired point cloud includes absolute coordinates, the duct location can be accurately reproduced later. Even after backfilling, AR display can virtually visualize the duct from the surface, making it immediately clear that “a previously scanned cable lies directly beneath this point.” This is extremely useful for preventing excavation accidents and planning work during future maintenance or other projects.

Additionally, underground duct data scanned with LRTK can be shared via the cloud so that headquarters design departments and other construction teams work from the same information. Wiring routes that may have been omitted or outdated in paper drawings can be accurately stored and shared as digital point cloud data, contributing to organizational knowledge accumulation. As a result, unexpected troubles can be avoided, shortening schedules and reducing costs.

AR-Based On-Site Information Sharing and Consensus Building

LRTK’s AR features and cloud sharing dramatically streamline information sharing between the field and stakeholders. Railway signal and communication works involve many parties—contractors, railway operators (clients), and designers—and ensuring everyone shares the same completion image is key to project success.

Consider installing a new signal near a level crossing. In the past, explanations relied on design drawings and perspective renderings to show “this equipment will be installed here,” but with LRTK AR you can show a life-size completion preview on site. Showing clients or nearby residents the post-construction scenery and equipment layout through a smartphone makes points that are difficult to convey with paper materials intuitive. This facilitates prior consensus building, helping prevent later disputes such as “this is different from what we were told.”

Even as construction progresses, conducting as-built confirmation with LRTK and sharing the data allows designers and managers in remote locations to provide immediate feedback. Reviewing cloud-based point clouds and photos in meetings enables understanding detailed conditions without visiting the site, accelerating decision-making. This real-time information sharing is effective for the tight schedules typical of railway construction, preventing rework due to mistakes and contributing to quality assurance.

Furthermore, data captured with LRTK serves as a valuable asset. Keeping point clouds and position information as a “digital archive” after construction allows efficient planning for the next maintenance cycle, and new engineers can study past conditions in 3D. In this way, LRTK functions as a platform that bridges the field and the office, the present and the future with data, contributing to smarter railway infrastructure management.

Conclusion: Take the First Step in On-Site DX with LRTK

DX (digital transformation) in the railway signal and communication infrastructure domain is an urgent issue. To efficiently renew and maintain aging equipment and continue safe, reliable work with limited personnel, smartening on-site operations is unavoidable. The LRTK introduced in this article is an easy-to-adopt solution as a first step toward such on-site DX.

LRTK, which enables high-precision surveying and 3D scanning with just a smartphone and a compact device, is easy to handle even without specialized knowledge and can be used intuitively by anyone on site. Surveying, drawing creation, and verification work that formerly took days can be completed on the spot with LRTK, directly delivering work efficiency improvements and cost reductions. Above all, by using data to allow all stakeholders to share the same “reality,” wasted effort and mistakes are reduced, improving safety and quality.

Start by introducing LRTK in part of an everyday construction project. Visualize the site with point cloud scanning and make future equipment visible with AR. These incremental steps will steadily advance DX in railway signal and communication infrastructure management. Embrace digital technology to make next-generation railway infrastructure maintenance and construction more efficient and sustainable. The door to on-site DX is already open. LRTK, as a leading-edge tool, will support your teams’ success in the field.