The Integrated Workload Scale (IWS): a new self-report tool to assess railway signaller workload

Area of Science:

• Human Factors
• Occupational Psychology
• Railway Operations

Background:

• Network Rail requires robust methods for assessing mental workload (MWL) in railway control staff.
• Existing MWL assessment tools needed refinement for the specific context of railway signalling.

Purpose of the Study:

• To develop and validate a new tool, the Integrated Workload Scale (IWS), for measuring the mental workload of UK railway signallers.
• To evaluate the IWS's effectiveness in simulator and field settings.

Main Methods:

• Development of the Integrated Workload Scale (IWS) based on a new MWL model.
• Testing the IWS in full-scale simulator trials (NX panel, IECC system).
• Field validation of the IWS in operational signal boxes.

Main Results:

• The IWS proved to be a valuable measure of individual experienced workload fluctuations over time and across scenarios.
• The scale demonstrated good acceptability among signallers.
• IWS results correlated well with timeline analysis and subject matter expert assessments of expected workload.

Conclusions:

• The Integrated Workload Scale (IWS) is a validated and acceptable tool for assessing mental workload (MWL) in railway signallers.
• The IWS provides reliable insights into experienced workload, aiding in operational safety and efficiency.
• This tool supports Network Rail's ongoing efforts to manage and understand staff workload.