In busy locations, signalling can be very challenging and stressful, in a manner similar to air traffic control. Signallers are therefore susceptible to stress-related illness. Following protracted industrial action from unions and, much more recently, detailed studies on fatigue and ergonomics in the rail industry,Rail Human Factors: Supporting the Integrated Railway, John R. Wilson et al, Ashgate, London, 2005People and Rail Systems: Human Factors at the Heart of the Railway, John R. Wilson et al, Ashgate, London, 2007 prudent operators implemented strict guidelines relating to the length and number of consecutive shifts permissible for safety-critical workers, including signallers. These guidelines are ideally aimed at improving safety and reducing fatigue at work, but also the overall lifestyle of employees. In some cases, physical changes in the work environment also followed these studies, including changes in the design of signal box lighting, seating and signalling equipment.
