2022-11-09, Stoller, Nicole, Wahrstätter, Stefan, Brüngger, Jonas, Fischer, Katrin

Background: Drivers of some public transport, like trams or buses, are equipped with a punctuality display to continuously monitor the actual status with the scheduled times of the timetable. The train drivers of the Swiss Federal Railways and some other major railway companies in the country do not have such a punctuality display until now. Instead, they receive other information aids on the screen of their work tablets, such as frequent passage times for operating points or recommended speeds for a smooth and energy-saving journey. However, train drivers must compare two displayed times and perform a mental calculation to get their current earliness or delay in relation to the timetable. Aim: The aim of this study was to investigate how a punctuality display needs to be designed to support drivers in a smooth and safe journey without causing stress or distraction. Method: Two prototype punctuality displays, a bar graph display and a numeric display, were developed in a workshop with experts from the railway and occupational psychology fields. During the development the two prototypes were evaluated according to suitable design and usability criteria such as task appropriateness, conformity to expectations or individuality. In addition, the two prototypes were not allowed to restrict the train drivers' scope of action or distract them during the journey. The train drivers tested the two punctuality displays on test tablets during one to two work shifts. They then rated usefulness, distraction, stress, risk of confusion and other issues on an online-questionnaire using a 7-point Likert scale. Results: Seventy-three train drivers tested the punctuality displays, 55 of whom completed the questionnaire. Eighty per cent of the drivers preferred the numerical display to the bar display. The ratings of some aspects, such as usefulness or interpretability, were significantly higher for the numeric display than for the bar display. Conclusion: The results show a clear preference for the numeric display over the bar display. While the usability criteria in this study were only considered for the punctuality display itself, they should also be applied when the system is put in place.

2022-09-26, Stoller, Nicole, Brüngger, Jonas, Wahrstätter, Stefan, Dittrich, Melisa, Nisoli, Giulio, Hostettler, Karin, Fischer, Katrin

Swiss railway companies provide their train drivers with modern communication devices such as cell phones and tablets. The use of these devices is necessary for train drivers to perform their tasks. However, the use of these devices can distract the drivers to an extent not to be underestimated. Increasing irregularities and unsafe actions, including signals passed at danger, can be attributed at least to a certain extent to the distraction of train drivers by these mobile and other digital devices in the driver’s cab. The final goal of this study was to identify appropriate measures to reduce distraction or its consequences without restricting the scope of action of the train drivers or hindering them in the performance of their primary tasks (i. e., safe train driving). We investigated which digital devices and which of their functions in the driver’s cab lead to distraction in what situations. For this purpose, we conducted 14 qualitative observations in the driver’s cab and six interviews with rail experts. Based on the results, we suggested how to address distraction in the driver’s cab from a work psychology and design perspective. To achieve a holistic approach, we developed measures that address the individual driver as well as the design of technology and the organizational processes. The development and validation of appropriate measures was realized in close collaboration with experts of several railway companies. The outcome is a set of 26 preventive and protective measures. Preventive measures aim to avoid distraction, e.g., by restricting irrelevant information from entering the driver’s cab during the ride. Protective measures reduce the negative consequences of distraction, e.g., the feature of manual and temporary suppression of incoming messages. By carefully selecting and implementing these measures, the railway companies can ultimately support their train drivers to use modern communication devices in the driver’s cab safely and sensibly.