In the rapid development of Chinese high-speed railway, the transportation complexity is increasing along with the increase of mileage and traffic. It puts higher requirements upon railway dispatchers, who are in the key positions to ensure rail safety and efficiency. Through the research of engineering psychology, investigating the cognitive processes of dispatchers in decision-making can provide support for further improving the operation of current system.
The Chinese high-speed railway dispatching system has a very high level of automation. In most circumstances, dispatchers only need to focus on monitoring operation with relatively medium level of workload. However, when an emergency occurs under which the automation system may not be able to handle independently, the dispatchers need to judge the complex situation and make safety-oriented decisions by their own. In these situations, their workload may increase abruptly and their decision may get impacted. Given the importance of the consequences, it is necessary to find out the important emergency scenarios, the critical decision-making, the factors that can affect their decisions, and the method to improve their decision- making process.
In order to answer these questions, we conducted four studies in the thesis. Study 1 systematically analyzed several important emergency scenarios by using task analysis method. We found earthquake disposal scenario is very important and the rapid response period is a critical decision-making stage in the process to handle earthquake. Further analysis showed that the dispatchers would first judge the epicenter and the range of the earthquake, and then stop trains according to their priority order until all trains in the dangerous zone are stopped. In the following studies, we quantitatively analyzed the relevant factors affecting this process. In Study 2, we analyzed the historical data to understand the factors that may influence the number of trains stopped by the dispatchers in quantitative manner. We found that higher earthquake magnitude and higher dispatcher's ability are linked with more trains being stopped. This suggests that such decisions are influenced by the formal operation regulations as well as the subjective safety margin of the dispatchers. Study 3 investigated how the priority to stop trains are influenced through experiment. We found that the dispatcher's priority judgment mainly follows a combination of center - first rule and a driving-in first rule. However, difficulties in locating the epicenter and the range of the earthquake may hinder the judgment. On the basis of study 3, study 4 further explored an intervention method to improve the judgment of train-stopping priority. We found that providing a simple visual display to show the epicenter and the range could significantly improve the accuracy of dispatcher's stopping priority judgment.
This study systematically analyzed several important emergency disposal scenarios, and conducted a systematic study on the critical decision-making cognitive process of earthquake emergency. We further quantitatively analyzed the factors that can affect the scope and the priority in train-stopping judgement, and explored an intervention method to improve the priority judgment. The study provides a human factor approach for improving the seismic emergency response process in Chinese high-speed railway dispatching and provides useful suggestions in accident safety analysis and prevention, personnel selection, training and the interactive interface design.
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