The use of Ultra-Wideband (UWB) technology in reporting the real-time location of resources (workers and equipment) is shown to be effective in improving the current safety monitoring practices. Since many site accidents occur when workers are struck by moving equipment or enter hazard-prone areas, it is important to evaluate the accuracy of the UWB RTLS in estimating the location of dynamic resources on construction sites. In this paper, the effects of variables, such as “speed” and “heading”, on the accuracy of the estimated location of dynamic tags are investigated. It is shown that the accuracy is inversely proportionate to the speed of the tag, the number of tags being tracked and the complexity of the path on which the tag is moving. A novel approach to defining “danger zones” on construction sites is also proposed through which the feasibility of using static tags to define the boundaries of forbidden areas on site is validated. The findings of this study indicate the applicability of UWB in locating dynamic resources on construction sites.