The train dispatchers of high speed railways (HSR) play an important role in guarantee the safety and efficiency of railway traffic. However,the task properties and potential human errors lied in the dispatching work is not fully understood.In this study, we intended to make atask analysis and examinethe possible human errors in HSRdispatchers' handling of the rail-switch breakdown, a relatively common equipment failure with a serious impact.

Toachieve these goals, we conducted semi-structured interviews with five experienced traindispatchers working on the newest centralized traffic control system of China’s HSR. We used the hierarchical task analysis (HTA) to understand their critical operations during the handling of rail-switch breakdown. Then we used the systematic human error reduction and prediction approach (SHERPA) to analyze possible human errors throughout the entire process.

We found that thisprocessinclude detecting the failure, notifying the train drivers to stop or slow down, attempting reinitiation, rescheduling to slow down the traffic, coordinating the repairment, and resuming the normal traffic.The most common human errors include: forget certain operations, conduct wrong operations, and failure to communicate specific information.

Wefurther discussed how these errors should be prevented.