MEASURING THE VARIABILITY OF THE PEDESTRIAN CROSSING FUNCTION IN THE SOCIO-TECHNICAL SYSTEM OF URBAN ROAD TRANSPORT

In some areas of transportation systems, reduction of risk using typical safety engineering tools can be difficult due to the relatively small number of events that can be analysed to draw conclusions for the future. One way out of this situation is to analyse systems in their normal operation when no adverse event occurs. It can be done, inter alia, with the Functional Resonance Analysis Method. An important research problem in this context is how to describe the variability of system functions. In this article, we propose an original method, based on the number of hazard sources present in a given analysis domain and apply it to a real pedestrian crossing. The obtained results indicate that the quantitative coincidence measures proposed by us are a convenient way to capture ‘functional vibrations’ in real socio-technical systems. This allows the prediction of undesired states of such systems based on their normal operation.