Railway signals passed at danger: A bibliometric analysis

Signal passed at danger (SPAD) is the most frequent cause of rail accidents as confirmed by relevant investigation in the field. The purpose of this paper was to identify the trends in SPAD research. Consequently, we aim to inspire and motivate future researchers, particularly academicians, to delve into this critical issue. Currently, the majority of researchers working on this topic are from the railway industry. For this reason, conducting a comprehensive review of existing research would yield significant value to both the academic and technical communities. This research examines the developments and accomplishments in this field concerning SPAD using the bibliometric library of R software from 1966 to the end of 2022. By bridging the gap in the existing literature, this research facilitates the global exchange of knowledge among railway experts, ultimately contributing to the reduction of safety risks and associated economic costs.