Visualizing to Protect Site Safety! The Importance of Real-Time Worker Location Management

Table of contents

• Challenges in managing on-site worker locations

• Benefits of real-time location management

• Technologies that support real-time location management

• Points and precautions when introducing the system

• Simple surveying with LRTK

• FAQ

Challenges in managing on-site worker locations

At job sites, accurately knowing who is doing what and where they are is indispensable for both safety management and schedule control. However, many sites currently lack a system to grasp each worker’s current position in real time, forcing managers to verify situations manually. For example, at large construction sites or plants, it is common to see supervisors contacting workers by radio or walking around vast areas to confirm people’s whereabouts. With these traditional methods, it takes time to obtain necessary information, which can lead to reduced work efficiency and schedule delays.

Moreover, not knowing workers’ locations poses major safety risks. If an accident or disaster occurs on site, it is essential to immediately know who is where to evacuate everyone swiftly or carry out rescue operations. Without real-time location information, confirming each person’s whereabouts can be time-consuming, delaying the initial response. In sites where heavy machinery and vehicles are moving about, workers may inadvertently approach hazardous areas where entry is prohibited; if location data is not visible, immediate warnings cannot be issued and the risk of a serious accident increases.

Thus, the inability to grasp and manage on-site worker location information in real time presents problems both in productivity and safety. Especially in the construction and civil engineering industries, chronic labor shortages and an aging workforce make site digitalization indispensable to maintain safe operations with limited personnel. Introducing real-time location management will become an increasingly important measure to address these challenges. To solve these issues, attention is focused on real-time location management systems that “visualize” worker positions using the latest ICT technologies.

Benefits of real-time location management

Visualizing worker positions in real time brings various benefits to site operations. First, in terms of improved productivity, managers can grasp the positions of all on-site workers at a glance on a PC or tablet screen. Because they can check in real time whether “too many people are concentrated in a particular area” or “the right personnel are assigned to the necessary tasks,” it becomes possible to allocate personnel without waste and issue smooth work instructions. Since supervisors no longer need to confirm by radio or search around each time, communication losses are reduced and work planning is streamlined.

Strengthening safety is another major benefit of real-time location management. A location information management system can implement features such as automatically sounding an alarm when a worker approaches a hazardous area, or detecting abnormal movements like falls and instantly notifying managers. If an accident does occur, being able to immediately identify “who is where” facilitates rapid rescue and evacuation guidance. Also, when the movements of all workers are understood, it is easier to take preventive measures against unauthorized entry into restricted areas or contact accidents.

Furthermore, by accumulating and analyzing location data, new improvements in site management can be discovered. For example, data on workers’ movement routes and dwell times can reveal inefficient traffic flows so layouts can be revised, or appropriate break timing can be considered. Using acquired data also helps objectively determine priority areas for safety patrols, contributing to a safer and more efficient workplace. Additionally, because history data of who worked where and when is automatically stored, it aids in causal investigations and rapid situation assessment if an accident occurs. Introducing real-time location management can raise the site’s safety culture and help build a more resilient safety management system.

Technologies that support real-time location management

To grasp worker locations in real time, it is necessary to utilize positioning technologies suited to the site environment. For open outdoor construction sites, GNSS (satellite positioning systems) represented by GPS is a strong candidate. If each worker carries a smartphone or a dedicated GPS device, position acquisition is relatively easy outdoors with a clear sky. GNSS alone has an error on the order of several meters (several ft), but that standard accuracy is sufficient to grasp approximate positions across a wide site. When higher accuracy is required, RTK (real-time kinematic) positioning using a base station can achieve centimeter-level positioning, but for typical safety management uses the standard GNSS accuracy is effective.

In indoor environments such as inside buildings or tunnels, satellite signals do not reach and GNSS cannot be used, so other technologies are needed. One widely used method is BLE beacons (Bluetooth Low Energy beacons). Small beacon transmitters are installed at various points indoors, and the worker’s smartphone or handheld device estimates position from the received signal strength. Accuracy is roughly a radius of a few meters (a few ft), but because installation costs are low and batteries power the beacons so wiring is unnecessary, they are easy to introduce on site. Also, since BLE beacons have a limited radio range, they are less likely to detect workers who have left the site, which makes it easier to take privacy into consideration.

Ultra-wideband (UWB) positioning technology is also attracting attention. Workers carry UWB-compatible tags and multiple antennas (base stations) are installed on site; distances are calculated from nanosecond-level round-trip radio times to perform high-precision trilateration. UWB positioning enables precise location tracking with errors of tens of centimeters or less and is increasingly adopted in environments that require high accuracy such as large plants or underground construction. However, introduction costs are higher than beacons and initial setup requires more effort, so selection should depend on necessity. Other technologies include Wi‑Fi positioning that uses existing Wi‑Fi signals, RFID tags for material management, and video analysis of surveillance cameras to determine people’s locations—various technologies are combined depending on site conditions.

In practice, it is common to operate by combining multiple technologies for outdoor and indoor environments. For example, a hybrid system can use GPS positioning via smartphones that workers carry outdoors, then switch to BLE beacon signals when they enter a building to continue tracking. Another approach uses small tags attached to workers’ helmets or safety vests, with dedicated receivers on site aggregating location information. The important thing is to choose technology that matches your site environment (outdoor vs. indoor, required accuracy, coverage area, etc.) and to establish infrastructure that can stably provide real-time positioning.

Points and precautions when introducing the system

When introducing such a real-time location management system to a site, there are several key points and precautions to keep in mind. First is technology selection and infrastructure design. As mentioned above, it is important to choose the optimal positioning method according to the site’s size, structure, and required accuracy. For example, in buildings with a lot of steel framing, radio waves reflect and attenuate easily, so you need to carefully plan antenna or beacon placement and install a sufficient number to avoid blind spots. Even outdoors, check in advance whether there are locations where signals may be interrupted due to terrain changes or tall cranes, and take measures such as installing repeaters if necessary. When using handheld devices or tags, pay attention to durability (dustproof, waterproof, and shock resistance) and battery life, and select equipment that can operate stably in harsh site environments.

Next, consider introduction costs in a planned manner. System implementation costs vary greatly depending on the chosen technology and the site area. Installing a few dozen relatively inexpensive BLE beacons can often start on a small budget, but deploying many high-precision UWB tags across a wide area requires a corresponding investment. Although hardware prices have been declining with the spread of IoT devices, instead of a full-scale rollout it is wise to begin with a pilot in a limited area to evaluate effectiveness and issues, and then expand step by step.

Also pay attention to privacy and gaining on-site staff understanding. Since location information is sensitive data, it is important to limit the information collected to what is necessary for work. For example, configure the system so it does not monitor workers’ detailed movements outside working hours or during breaks, and manage access rights to the collected data so unrelated personnel cannot view individuals’ activity histories. Before introduction, carefully explain to employees that the system’s purpose is safety assurance and operational efficiency, and not surveillance. Removing workers’ concerns and obtaining their cooperation is key to embedding the system and maximizing its benefits.

Finally, do not forget to prepare an operational framework. Building an environment that can acquire location information in real time is not enough; you must prepare personnel and workflows to utilize that information. For example, assign a dedicated safety manager to monitor screens and ensure rapid on-site contact and response when abnormalities are detected, and regularly analyze system logs and feed findings back into safety meetings. Also, make sure each worker follows basic operational rules such as carrying and charging devices. By including these organizational preparations in your implementation plan, the real-time location management system will become a truly “usable” tool that contributes to strengthening site safety.

Simple surveying with LRTK

To realize real-time on-site location information management, it is essential not only to build positioning infrastructure but also to grasp accurate coordinate data for buildings and reference points at the site. For example, when installing beacons or antennas for indoor positioning, accurately measuring and registering the installation coordinates in advance allows the system to display locations with higher precision. However, traditional surveying requires specialist technicians and expensive equipment, making it difficult for site personnel to perform easily.

LRTK-based simple surveying is attracting attention as a solution. LRTK is an innovative tool that achieves centimeter-level positioning by linking with smartphones and tablets; by attaching a dedicated ultra-compact GNSS receiver to a smartphone, anyone can easily obtain accurate coordinate positions. For example, a site manager can walk through a building and measure important points with LRTK, digitizing floor plans and equipment locations on the spot. Tasks that used to require a surveying company and half a day can now be performed quickly by site staff, enabling “measure when you need to.”

With our LRTK series, obtained coordinate data can be immediately uploaded to the cloud and results checked in real time from an office PC. You can instantly verify whether measured points match drawings on the spot, share data with colleagues in remote locations to proceed with work, and dramatically improve surveying efficiency on site. It also includes features such as elevation measurement, automatic calculation of distances and areas, and AR-based installation guidance, making it a versatile on-site tool beyond mere surveying equipment.

In building a real-time location management system, simple surveying with LRTK provides powerful support. For example, when placing BLE beacons for an indoor positioning system, measuring and registering each beacon’s accurate coordinates with LRTK contributes to improved tracking accuracy later. When re-measuring existing facility dimensions prior to renovation, LRTK enables the rapid acquisition of precise as‑built data. By leveraging such modern tools, management of people and asset location information can be made smoother and more accurate, strongly supporting the creation of safer and more efficient sites.

The LRTK series is a solution that achieves reduced work time and improved productivity through high‑precision GNSS positioning in construction, civil engineering, and surveying fields. It is compatible with the Ministry of Land, Infrastructure, Transport and Tourism’s i-Construction initiative, and with its affordable pricing aimed at the “one-device-per-person all-purpose surveying instrument,” it has already been adopted at many sites. For details on LRTK, please refer to the official website. If you have questions about the product or would like to request a demo, please feel free to contact us via the inquiry form. With LRTK, let’s evolve site safety management and surveying work to the next stage.

FAQ

Q1. Why can’t GPS be used indoors or underground? A. GPS measures position using radio signals from satellites, but inside buildings or underground the satellite signals are blocked by walls or the ground and cannot reach the receiver. As a result, GPS receivers cannot lock onto satellites indoors or inside tunnels and cannot obtain accurate positions. In such locations, dedicated indoor positioning technologies such as BLE beacons or UWB must be used instead of GPS.

Q2. How accurate can worker location information be? A. Accuracy depends on the technology used. General GPS typically has errors on the order of several meters (several ft). BLE beacon-based systems also estimate position within a radius of a few meters (a few ft). On the other hand, introducing UWB positioning can achieve accuracy of tens of centimeters or less (tens of inches or less). Wi‑Fi positioning accuracy depends on the environment but is typically from a few meters to over ten meters (a few ft to over ten ft). It is important to select the optimal technology based on the required accuracy.

Q3. Do workers need to carry smartphones? A. Using smartphones is an easy and effective method, but it is not necessary for everyone to carry one. In some sites, workers carry dedicated small GPS trackers or UWB tags and the management side tracks positions. If using smartphones, you can either install an app on workers’ personal phones or provide company smartphones. The advantages of dedicated tags are robustness and long battery life, while the advantages of smartphones include on‑screen alerts and communication. Choose the method that best fits site needs and budget.

Q4. Is the cost to introduce a real-time location management system high? A. Implementation costs vary depending on the chosen technology and site scale. Systems using simple beacons can often be started at relatively low cost, but covering large areas with high precision requires significant investment. However, by conducting a small-scale pilot to verify effectiveness and then expanding gradually, you can build the system while controlling costs. Device prices have been decreasing in recent years, making introduction easier than before.

Q5. Do we need to consider workers’ privacy? A. Yes. Location information is personal data and requires careful consideration. Limit the information collected to what is necessary for business, and configure the system not to track movements outside working hours. Manage access rights to location data so that personal activity histories are not viewed unnecessarily for purposes other than site management. When introducing the system, explain to employees that its purpose is safety and efficiency, not surveillance, and obtain their understanding and cooperation.

Q6. Can accurate reference points be measured without specialized surveying equipment? A. Recently, simple surveying tools that use smartphones have emerged, with LRTK being a representative example. With LRTK, attaching a small GNSS receiver to a smartphone and pressing a button allows anyone to measure coordinates with centimeter-level accuracy (half-inch accuracy) without specialist knowledge. Using this, reference point surveying and alignment work that previously relied on specialists can be performed quickly by site staff.