Real-time construction site monitoring requires real-time tracking of resources. Recent researches in real-time data collection have transformed traditional construction practices and skyrocketed productivity, safety and quality on site while serving as a basis for tremendous cost savings. This paper studies available literature to identify and map several types of real-time data that can be collected directly or indirectly on a construction site. For some analyses, real-time automated data collected is not feasible and human intervention is required to record desired information. This paper will focus on construction safety and classify the factors that pertain to worker safety. Systematic Literature Review (SLR) method will be used to map the factors and technologies that have been tested on sites for construction safety. The research will explore both hard data (like location and physiological status) and soft data (like attitude and experience of workers, and information pertaining to safety training and safety culture in an organization). This paper will serve as an index for researchers and practitioners working on construction safety or wanting to learn about real-time construction worker safety research. The maps resulting from this study will serve as a guide to understand what data types are required for a specific problem, how to collect them and how the data can be analyzed. The maps will also reveal trends in automation and technologies use in construction safety research with respect to time.