Proposal of a Driving Posture for Fatigue Reduction Based on Manysided Evaluations

Abstract

Fatigue resulting from long-term driving can be classified into physical and mental fatigue. Physical fatigue seems to be mainly caused by driving posture. The purpose of this study is to develop a new driving posture for reduction of causal factors of physical fatigue, that is, biomechanical loads caused by the posture. In this paper, driving posture was optimized by subjective adjustments of sitting posture and seat contours considering necessary conditions for driving operations and forward view. The new driving posture was validated by biomechanical analysis of musculo-skeletal loads and contact loads. The posture was also evaluated in dynamic long-term driving by qualitative and quantitative measurements. The results showed physical fatigue of the new posture was halved in comparison with the one of the conventional posture in same car by subjective evaluations. Therefore, fatigue reduction of the new posture was qualitatively validated. Physiological indices had same tendency with subjective evaluations. From the results, we extracted six physiological indices as good measures of physical fatigue during driving. The effects of physical fatigue were also observed at various levels of human system. Therefore, physical fatigue reduction of the new posture was quantitatively validated by physiological measurements.