Questioning Human Error Probabilities in Railways

Human errors are regarded as one of the main causes for railway accidents these days. In spite of this fact, the consideration of human error probabilities in quantified risk analyses has been very rudimentary up to now. A lack of comprehensive data and analyses in literature lead to the use of estimations and values from other industries. This paper discusses the transferability of human error probabilities for railways and identifies problems in handling methods and values. A model of working systems is used to demonstrate the particularities of railway work places and to derive a structure for performance shaping factors that influence the human error probability. A holistic approach is proposed to support the determination of appropriate human error probabilities for railways.