Measurement of Travel Fatigue

Abstract

Using both objective monitoring and subjective estimation, this paper investigates travel fatigue. Objective monitoring included an experiment designed to measure energy expenditure rates with a heart rate monitor while travelers walked on level ground, went up and down stairs, and rode on a bus and subway. Free modulus magnitude estimation was used to investigate travelers’ subjective perceptions of fatigue while traveling. The results of the two parts were compared to understand their relationship. The results showed that the energy expenditure rate was sensitive not only to travel mode, represented by running vehicle acceleration, but also to posture, carrying personal belongings, and in-vehicle crowding. According to participants’ subjective perceptions, the effect of in-vehicle crowding was greater than carrying a 3.8-kg burden; the fatigue rates of standing, both with and without a load, tended to be subjectively overestimated compared with normally transformed energy expenditure rates. Numerical results from a case study in Zhongshan, China, and an online survey of bigger cities in China showed that travel time is not the only issue. Travel fatigue must also be considered in planning urban transportation systems and in evaluating transit service quality and has great potential for predicting choice of travel mode.