Construction Site Safety Management Evolves: Introducing the Latest Measures in Civil Engineering and Construction Aiming for Zero Occupational Accidents

Introduction

Construction sites are always accompanied by the risk of occupational accidents. High-altitude work and the operation of heavy machinery create a variety of hazards in civil engineering and construction sites, making thorough safety management the top priority. In fact, the number of fatalities in the construction industry reaches around 300 per year, making it disproportionately high among all industries. Among these, falls from height and collisions with heavy machinery rank high as causes of fatal accidents, and strengthening countermeasures in these areas is essential to achieve zero occupational accidents (zero accidents).

Traditionally, on-site safety management has relied heavily on human oversight and experience—morning briefings, safety patrols, and training for workers—making oversights and human error inevitable. However, in recent years, the use of rapidly advancing digital technologies and AI has enabled the visualization of safety management. This article focuses on the evolution of safety management at construction sites, particularly on the two areas of fall prevention and prevention of contact with heavy machinery, detailing current challenges and causes of accidents, the latest technological countermeasures, case studies and their effects, and the regulatory background. We hope this helps you grasp the latest safety management trends and consider priorities for achieving zero occupational accidents.

Current Situation and Challenges in Preventing Falls

The most frequent cause of fatal accidents in construction is falls from heights. Incidents such as falling from scaffolding, falling through openings, or falling from roofs and beams are common in high-altitude work. According to statistics from the Ministry of Health, Labour and Welfare, about 40% of fatal accidents in the construction industry are due to falls. The following issues are cited as underlying causes of such fall accidents:

• Inadequate safety measures: There are cases where work proceeds with insufficient fall-prevention equipment, such as missing guardrails on temporary scaffolding, defective work platforms, or absent safety nets. Some sites also lack adequate fall-prevention barriers at the edges of roofs or openings.

• Non-use or improper use of safety belts (fall-arrest equipment): Some workers fail to correctly wear traditional body-belt-type safety harnesses or work without lifelines entirely, which can lead to fatal falls. For high-altitude work, wearing safety belts and securely hooking to a lifeline is essential, but negligence or overconfidence such as "I’ll be fine" can result in noncompliance.

• Procedural and awareness issues: Human errors such as stepping backward off a scaffold during demolition, or losing balance while moving on scaffolding, are frequent. Lack of adherence to safety procedures, inexperience, and lapses in attention remain significant problems.

Regarding current measures and regulations, Japan’s 2019 revision to the Industrial Safety and Health Act made it mandatory to use "fall-arrest equipment" (commonly referred to as safety belts) when work is conducted at heights of 2 m or more and a work platform or guardrail cannot be provided. In particular, wearing full-harness-type safety belts has become the standard, and from January 2022 the use of the old-style body-belt-type safety harness has been completely banned. Following this legal revision, adoption of full harnesses has spread from major general contractors to small and medium-sized construction sites, and some effects have already been observed—for example, the number of fatal fall accidents in construction decreased in 2019 by about 26 compared to the previous year. However, even when safety belts are worn, improper use or insufficient height that still allows impact with the ground have been reported, so a shift in awareness toward "using equipment correctly" remains crucial beyond equipment performance alone.

Thus, while equipment and regulatory measures for fall prevention are advancing, raising on-site awareness and preventing human error remain challenges. In response, recent years have seen the introduction of cutting-edge fall-prevention technologies at sites to complement human oversights.

Latest Technologies and Case Examples for Fall Prevention

To reduce fall accidents, a variety of technology-driven safety measures are emerging in civil engineering and construction. Here are examples of state-of-the-art technologies effective for preventing falls from heights:

• AI surveillance cameras for PPE compliance checks and hazardous area monitoring: Systems are now available that use AI to analyze live camera footage on site to automatically check whether workers are correctly wearing helmets and safety belts. For example, if AI detects an unbelted worker on a steel frame, it can immediately notify a manager’s smartphone for on-site intervention. Cameras can also track human movement and trigger alarms when workers are about to enter restricted areas. By enabling AI to monitor high-altitude work 24/7—tasks previously reliant on human observation—these systems can compensate for human oversights and prevent accidents. Shimizu Corporation, for instance, has applied the AI-equipped camera system "Kawasemi" not only to heavy equipment but also to monitor high-altitude work, issuing alarms when people enter hazardous areas. The introduction of such AI surveillance technology is expected to significantly reduce near-miss incidents.

• Wearable sensors for monitoring workers: Small wearable devices for workers are becoming widespread as another safety solution. Wristwatch-style or helmet-mounted sensors collect real-time location and movement data and can detect impacts from falls or drops, instantly issuing alerts. If a worker falls from a height or loses balance on a scaffold, the sensors capture the abnormal acceleration and notify nearby workers or supervisors via buzzers or messages. This enables rapid rescue activities, helping prevent secondary injuries and minimizing harm. Some wearables also monitor heart rate, body temperature, and humidity to detect heatstroke risk, aiding in the prevention of fainting or falls due to poor physical condition. Aggregated location data from these sensors can be used remotely to see "who is where" and whether anyone is approaching a dangerous area, enabling area intrusion detection systems that automatically warn when personnel enter a high-altitude work zone.

• VR-based experiential safety training: To fundamentally reduce fall disasters, improving each worker’s safety awareness is vital. VR-based immersive safety training has proven effective. Workers wearing VR goggles stand in a virtual high-altitude construction site and experience realistic scenarios such as falling from scaffolding or near-miss situations when safety belts are not used. For example, the VR safety training system offered by Nishio Rent All, called "Real Hat®", recreates scenarios such as falls due to defective scaffolding, dropped materials from cranes, and being trapped between a backhoe and a wall【※】. Participants experience accidents from the victim’s perspective, which helps them internalize how dangerous a fall from height can be and strongly discourages repeating the same mistakes. Immersive VR education differs markedly from lectures or video viewing and leaves a deep impression about the importance of proper harness use and guardrail installation. As a result, workers’ hazard prediction abilities (quality of KY activities) and compliance with safe behaviors improve, reducing human errors on site.

*(※The "Real Hat" VR safety system allows participants to virtually experience various real accident cases and discuss causes and countermeasures, contributing to heightened safety awareness. It is registered in the MLIT’s NETIS (New Technology Information System) and is being adopted by construction companies nationwide.)*

As described above, AI, IoT, and VR-based measures are transforming safety management for high-altitude work. Alongside physical improvements in protective equipment like full harnesses, digital technologies that compensate for human inattention and lack of experience are being put in place, making zero fall incidents an attainable goal.

Current Situation and Challenges in Preventing Contact with Heavy Machinery

Another major cause of serious accidents on construction sites is contact with heavy machinery. Accidents involving workers being caught in or struck by heavy equipment—such as backhoes (hydraulic excavators), bulldozers, cranes, and dump trucks—are frequent. While statistically second to falls as a cause of fatal accidents in construction (and sometimes underrepresented depending on classification methods), these are highly serious incidents, often occurring when workers are in the blind spots during a machine’s swing or reverse operations.

Key causes of heavy machinery contact accidents include:

• Operator blind spots: Large machinery has substantial bodywork, and broad blind spots—especially to the rear and sides—exist where the operator cannot see. When machinery is moved without a guide person, workers or other vehicles may enter these blind areas and be struck. Tragic cases occur when workers walking behind a reversing machine are not noticed and are hit.

• Lack of guidance and poor communication: Although a guide person is supposed to be present when visibility is poor, in practice guides are sometimes omitted for "short moves," or machines are moved before signals are clearly communicated. Miscommunication or poor coordination between the guide and the operator contributes to contact accidents.

• Insufficient area checks and sudden intrusions: Focused work can lead to inadequate safety checks around equipment, or walking workers may inadvertently enter machine operation zones. For example, workers conducting surveys or arranging materials inside an equipment area may be struck if timing is poor. There are also cases where a worker suddenly appears from a blind spot while a construction vehicle is moving on site and is struck.

Traditional countermeasures for machinery-related accidents include stringent qualification and skill training, separating people and machines through work planning, and deploying guide personnel. Legally, operating cranes or vehicle-mounted construction machinery requires certification, and regular safety training and equipment inspections are mandated. Nonetheless, human error and inattention cannot be completely eliminated, and the dilemma of "if only the machines weren’t here" or "if only people would stay away" has persisted on sites.

Recently, however, solutions leveraging advanced technologies have emerged to address this "human-machine contact risk," enabling dramatic improvements in safety. The next section reviews cutting-edge technologies and case studies aimed at preventing contact with heavy machinery.

Latest Technologies and Case Examples for Preventing Machinery Contact

To reduce the risk of human-machine contact, the construction industry is adopting IoT- and AI-based safety systems. Below are examples of state-of-the-art measures against machinery contact accidents:

• Machine-mounted AI cameras for blind-spot monitoring and alarm systems: Practical systems now mount AI-capable cameras directly on machinery to automatically monitor hazardous rear and side areas that the operator cannot see. A representative example is the vehicle-mounted safety monitoring camera "Kawasemi" developed by Shimizu Corporation. This system equips the rear of machinery with wide-angle cameras and image-analysis AI to perform near-360-degree continuous monitoring. When AI detects a person or vehicle, it instantaneously determines the situation and, if a worker comes within a preset distance, activates warning sounds and strobe lights to notify the operator. Simultaneously, large audible and visual alerts warn nearby workers, making the hazard mutually apparent. Thus, even if someone enters an operator’s blind spot, the system enables immediate recognition and, when combined with functions that automatically stop machinery, can prevent collisions. At sites using Kawasemi, reports indicate that "near-miss incidents during reversing have dropped to zero," with the AI camera serving as a "third eye" for machinery. Advanced image-analysis AI can also detect worker posture and gaze; for example, it can trigger a stronger alarm if a worker’s back is turned toward the machine (indicating they are unaware of the hazard), evolving into next-generation systems that make unobservant workers become aware of approaching danger.

• Proximity alert systems (proximity alarms) and safety zone management: Proximity detection systems, where both the machine and the worker carry sensors or transmitters that trigger alarms when a preset distance is breached, are becoming common. For instance, workers’ helmets or safety vests equipped with UWB (ultra-wideband) or RFID tags communicate with receiving antennas on the machine. If a worker approaches within, say, 5 m of the machine, a buzzer sounds in the cab while the worker’s tag vibrates to warn them. This mutual awareness greatly reduces near-misses. The system is especially effective during nighttime or in noisy environments, and some sites report a sharp decrease in near-miss reports after implementation. Additionally, GPS or high-precision GNSS-based location management systems visualize machine operation areas and no-entry zones on a digital map, sending smartphone alerts when workers mistakenly enter hazardous zones. These proximity alert and area-monitoring systems function as a barrier to keep people away from machines, fundamentally lowering the risk of contact accidents.

• Remote operation and automated construction to separate people from machines: The ultimate way to eliminate machinery contact accidents is to ensure that people do not need to be near dangerous machine operations. Under MLIT-led initiatives such as i-Construction and broader construction DX efforts, remote operation and autonomous machinery technologies are advancing. Examples include systems that allow excavators to be operated remotely from an office via communication lines so that no personnel need be on site for digging, and driverless dump trucks that autonomously navigate while avoiding obstacles using AI. Although still in limited use, these technologies are being demonstrated for disaster recovery and hazardous slope-shaping tasks, making constructing without humans riding or approaching machinery increasingly feasible. As remote and automated construction spreads, the risk of contact accidents will drop dramatically. However, because human-machine collaboration remains unavoidable on most typical sites today, developments continue for interlock-type safety devices that combine AI cameras and sensors to automatically stop machinery when people approach. Once these technologies become standard equipment, safety around heavy machinery is expected to improve dramatically.

Thus, layered safety nets to prevent "people-versus-machinery" accidents are being constructed through technology: AI continuously monitors and issues alerts, wearables and sensors track relative positions, and ultimately unmanned construction prevents exposing humans to hazards. A clear roadmap toward zero machinery contact incidents is steadily taking shape.

Regulations and Industry Initiatives Supporting Safety Management

Alongside technological adoption, laws and industry initiatives are reinforcing safety management at construction sites. Japan’s Industrial Safety and Health Act and related regulations set detailed safety standards for high-altitude and heavy-equipment work, which employers are obligated to follow. Examples include the aforementioned requirement to use fall-arrest equipment when no work platform is available at heights of 2 m or more, the placement of qualified crane operators, measures to prevent people from entering the working radius of equipment like backhoes, and conducting periodic self-inspections. Violations can result in penalties, making legal compliance a fundamental on-site requirement.

Recent regulatory trends have strengthened safety: the mandatory use of full-harness-type safety belts (fully enforced in 2022), stricter requirements for rearward visibility on construction machinery, and making efforts to provide workers with hazard experience training. The Ministry of Health, Labour and Welfare and construction industry organizations formulate a "Labor Accident Prevention Plan" every five years; for construction the plan sets clear numerical targets such as reducing fatal accidents by more than 15%, advancing the zero-accident movement. In the 14th Labor Accident Prevention Plan starting FY2023, construction remains a priority industry, with fall and machinery accident prevention as core pillars.

At the corporate level, major general contractors are actively promoting safety visualization and cultivating a safety culture. Concrete measures include systems for sharing near-miss incidents across sites, revitalizing safety meetings (hazard prediction activities: KY), and senior management conducting site patrols—actions that foster a corporate culture prioritizing safety. Information exchange on new technologies is occurring across the industry, and promising safety devices and systems are being proactively adopted. For example, multiple major firms are advancing the adoption of IoT sensor-based worker location management systems and developing unsafe behavior detection systems using AI cameras, sometimes through joint research toward standardization.

As a result of regulatory improvements and voluntary corporate initiatives, the long-term trend shows a steady decline in the incidence of occupational accidents in construction. Compared with 50 years ago, the number of fatal accidents has fallen to less than one-ninth. Nevertheless, the construction sector’s fatality rate remains high compared to other industries, and safety measures remain an urgent priority. Ensuring that everyone who works on site returns home safely requires mobilizing law, education, and technology to continually evolve safety management.

Improving Surveying Safety with LRTK

The latest safety measures are not limited to high-altitude and heavy-equipment tasks. Even ancillary work such as surveying and as-built checks benefits from new technologies that enhance safety. A prime example is LRTK, a simple surveying method that combines a smartphone with a high-precision GNSS receiver. LRTK (Local RTK) uses a palm-sized RTK-GNSS unit attached to a smartphone to achieve centimeter-level positioning, a groundbreaking tool increasingly used in civil engineering surveying.

Traditionally, surveying and layout work in civil engineering required surveyors to set up transits or GPS equipment near areas where heavy machinery operated, often necessitating that the surveyor come close to operating equipment and thus exposing them to contact risk. With LRTK, coordinates can be obtained quickly with a smartphone, dramatically shortening surveying time. For example, stake-out points for roadworks can be quickly measured with a smartphone and compact GNSS, allowing tasks to be completed safely during brief windows when machinery is idle. Reducing the time surveyors spend near operating machines directly reduces risk.

LRTK also includes AR (augmented reality) features and photo-based measurement functions, enabling remote point measurement without directly entering hazardous areas. For instance, in steep slopes or deep excavations where human access is dangerous, one can point a smartphone camera from a safe distance to obtain coordinates of target objects. This non-contact measurement eliminates risks from awkward postures or stepping into fall-prone areas. Moreover, LRTK can instantly plot measured coordinates on a cloud map, allowing the team to share which areas have been surveyed and which are hazardous. By visualizing no-entry zones and machine operation ranges on a high-precision GNSS-based work-area map, surveyors can confirm safe standpoints on their screens and maintain a safe distance from machinery while working.

Thus, LRTK’s simple surveying technology not only improves productivity but also provides the ancillary safety benefit of substantially reducing the risk of surveyors coming into contact with heavy equipment and helping them maintain safe separation. On sites that have introduced LRTK, near-misses involving surveyors and machinery have decreased, and staff report that “we can safely operate machinery even while surveying.” Going forward, the use of such smart surveying devices is expected to spread, establishing a working style that visualizes hazardous zones while enabling efficient work.

Conclusion

Safety management in civil engineering and construction is undergoing a major transformation driven by technological advances and on-site ingenuity. We have reviewed the latest measures for the two main challenges—fall prevention and machinery contact prevention—including AI surveillance cameras, wearable sensors, VR training, remote monitoring systems, and alert devices. These implementations can compensate for the limitations of human observation and fill gaps caused by human error, and quantitative results such as reductions in accident numbers and near-misses have been reported in various places. The effects of technology are beginning to show in the data, such as reduced fall fatalities following full-harness mandates and continued zero machinery accidents after AI alarm systems were adopted.

That said, the final line of defense remains the safety awareness of each person working on site. No device can be effective if not used. It is essential to evolve safety management through the triad of technology, education, and rules. Fortunately, under trends like work-style reform and DX promotion, balancing safety and productivity has become a major industry theme. Investing in smart safety management not only protects workers’ lives but also directly enhances site reliability, and its priority will only grow.

Achieving zero accidents requires fresh thinking and relentless improvement. The latest measures introduced here are only part of the effort, but by combining technological capabilities with on-site expertise, the goal of "zero occupational accidents" is no longer an unreachable dream. The evolution of construction site safety management continues, and the entire civil engineering and construction industry is striving to create future worksites where all workers can work with peace of mind.