IoT contributions to the safety of construction sites: A comprehensive review of recent advances, limitations, and suggestions for future directions

The construction industry, known for its high-risk environment, consistently experiences a significant number of fatalities globally. Mitigating these risks and ensuring safety on construction sites is paramount to preventing critical health incidents and avoiding substantial financial losses. Among the numerous methods to enhance site safety, the adoption of the Internet of Things (IoT) has emerged as a notable trend. Despite its importance, a comprehensive and up-to-date exploration of IoT's contribution to construction site safety is notably absent in existing review papers. This paper fills this gap by providing an in-depth analysis of IoT applications in enhancing construction site safety, drawing from a review of 147 publications up to June 2024. Employing a mixed-method approach that merges scientometric and systematic reviews, this study provides a broad overview of the current state and future directions in this field. The scientometric analysis illuminates a burgeoning research interest in IoT for construction safety, highlighting active regions through annual research trends, keyword maps, and citation burst maps. The systematic review categorizes the literature into three main dimensions: labor monitoring, environmental monitoring, and site and activities monitoring, underscored by the integration of IoT in advancing safety management. Despite significant progress in promoting IoT for construction site safety, the systematic review findings revealed several critical gaps. These include the need for selfmonitoring systems to autonomously detect sensor malfunctions, sensor-integrated personal protective equipment (PPE) enhancements to improve comfort and compliance, and addressing biases introduced by laborer attitudes requiring high compliance with safety protocols. Additionally, there is a lack of research on the application and impact of IoT devices in specific contexts, such as water occupancy projects and the effect of underground water on tunnel project safety. Furthermore, developing systems capable of monitoring dynamic hazards and providing spatiotemporal risk assessments is essential. The safety of storage areas for hazardous materials and monitoring vehicle conditions on construction sites also require more focused attention. This research proposes future directions to address these gaps and outlines the necessary sensors to enhance construction site safety and operational efficiency significantly.