The Risk Matrix in Railway - Is it Aligned with the Organization's Safety Targets?

Author(s) A. Fang, B. Pasquier, M. Khattra
Published as part of 102nd Transportation Research Board Annual Conference Proceedings, January 8-12, 2023, Washington, D.C.


The risk matrix has been a widely used tool for risk assessment in the railway industry. Railway organizations set safety targets and use risk matrices to control risks from all sources, to achieve these safety targets. However, if the linkage between the organizational safety targets and the risk matrix is not established, there is a high likelihood that the risk matrix will not be effective in achieving the overall safety targets. In this paper, a practical calibration method to align the risk matrix with safety targets is proposed and discussed. The risk matrix as a risk assessment tool has its own limitations which may result in uncertainties or even errors in risk assessment results. In addition to risk matrix calibration, improved design and proper use of risk matrix are also critical in achieving the safety targets. In this paper, lessons learned from the application of the risk matrix in various railway projects are summarized and compared to theories from previous research. Recommendations are made on improving the design and use of the risk matrix to overcome its limitations. By risk matrix calibration, proper design and usage of the risk matrix, railway organizations can build confidence that the established risk matrix is appropriate for the organization’s size, complexity of operation and is sufficient to achieve the desired safety targets.