Human vigilance in railway and long-haul flight operation

Abstract

Human operators in transport operations are often confronted with monotony, boredom, and irregular work schedules. This situation has become increasingly more acute because of the growing automation of systems. This paper presents methodology and preliminary results for two field studies on the vigilance of train drivers and long-range aircrews. The aim of these studies was to identify factors that can modify vigilance and to elaborate several specific solutions for reactivation. The method is based on the collection of physiological data in the field and on task observation of the operators. The recorded physiological data (EEG, EOG, EKG) permit an evaluation of vigilance and mental workload. The rest-activity cycles are estimated by actometry. The use of EEG and EOG are discussed in relation to monotony and sleep deprivation. For pilots, results show a high occurrence of decreased vigilance, particularly during phases of low workload (i.e., when cruising). Furthermore, it was shown that these periods of lowered vigilance can occur at the same time for two crew members. A great number of incidents of decreased vigilance were also observed for the train drivers. These incidents occurred even though the operators sometimes had high levels of activity. A direct relation was also noted between sleep duration and the onset of rest. These studies provide several means for maintaining vigilance during activities and improving the system of work schedule rotation.

Driving monotonous routes in a train simulator: the effect of task demand on driving performance and subjective experience

“…If the driver fails to respond again within another predetermined amount of time, the emergency brakes are applied and the train is brought to a stop (ITSRR 2005). However, there is evidence to suggest that drivers are able to respond to these devices during stages of very low arousal and alertness as the response becomes automatic and requires no conscious input by the driver (Peter et al 1983, Cabon et al 1993). The repetitive low demand nature of these sensory vigilance devices may subsequently also increase the monotony inherent in the driving task, especially under the driving conditions when a vigilance device would be most helpful (i.e.…”

“…The nature of the operating environment requires these workers to remain constantly alert for long periods of time, often under monotonous conditions, and to respond immediately to critical events or signals (Edkins and Pollock 1997). Thus, transport industry workers may be exposed to a variety of factors that can compromise alertness due to sleeprelated problems stemming from shift work and to task-related factors, such as monotony or low workload, that are an inherent part of their work (Cabon et al 1993). There is strong evidence to suggest that task-related factors can impair performance and induce fatigue independent of sleep-related factors, however, further work is needed to determine the types of tasks that are most at risk of performance deficiencies (Williamson et al 2011).…”

Biological and psychological rhythms: An integrative approach to rhythm disturbances in autistic disorder

“…Shift work is also known to be associated with increased risks of sleepiness at work (Akerstedt, 1988;Cabon et al, 1993), major accidents (e.g., Exxon Valdez (NTSB, 1989) or Three Mile Island (Moss and Sills, 1981)) and occupational accidents (Folkard and Tucker, 2003;Folkard and Akerstedt, 2004). The prevention of the negative effects of shift work and the treatment of associated symptoms may entail behavioral and educational programs, bright light therapy (Budnick et al, 1995;Horowitz et al, 2005) or pharmacology (Walsh et al, 1991).…”

The Operational Demand Evaluation Checklist (ODEC) of workload for railway signalling

“…For train drivers there have been some reports of psychophysiological measurements of workload (e.g. Caban et al, 1993 andMyrtek et al, 1994), and Hamilton and Clarke (2005) developed and proposed ATLAS as an analytical tool to assess train driver workload, from an information-processing angle. For signalling, there have been one or two contributions.…”