STRESS AND STRAIN OF SHORT HAUL BUS DRIVERS - PSYCHOPHYSIOLOGY AS A DESIGN-ORIENTED METHOD FOR ANALYSIS

Psychophysiological measures offer objective information for workplace design according to user requirements. They are, however, rarely appl ied in industrial practice due to weak points from the designer's poin t of view, such as the differentiation of various superimposed stresso rs, inter-individual differences, and the effort required for data aqu isition and handling. In this study a set of psychophysiological metho ds was used to analyse bus driver workplaces as a basis for redesign, and afterwards to evaluate design improvements. During inner-city oper ation bus drivers are exposed to a particular workload situation, espe cially due to the high density of traffic and bus stops. Their job is characterized by highly frequent and often simultaneous task execution , performed with a compulsory body posture and under exposure to vibra tion and noise. To reduce the workload related to the equipment and ta sks of bus driving, a research project was initiated to design a new d river workplace that meets the specific ergonomic requirements of the drivers. A detailed workload analysis, consisting of a task analysis, a strain analysis derived from ECG measures and an eye movement analys is was performed during public bus driving in different cities and wit h different drivers and bus types. Although the results have to be con sidered as somewhat limited owing to the methodological restraints and conditions of a field study, they provided valuable guidance for desi gn. A new concept for the driver cabin was created based on this datab ase. After installation, this design was evaluated by similar psychoph ysiological measures. Comparison of the pre-and post results indicates that the redesigned work station reduced workload levels.