Driving performance in new mothers: The mediating role of persistent fatigue

The link between driver fatigue and an elevated risk of traffic crashes has been firmly established, with most studies focusing on the effects of acute fatigue induced by sleepiness. However, specific demographic segments experience persistent fatigue, which, although similar to acute fatigue, requires distinct mitigation strategies. New parents, particularly within the first two years of their baby's life, are especially vulnerable to prolonged fatigue, potentially impairing their driving abilities and increasing the likelihood of crashes. Yet, there is a lack of research on the impact of this type of fatigue in this subgroup. We evaluated the driving performance of two groups of women: one comprised of mothers with infant children under 2 years old (n=66) and the other without infant children (n=46). We used a driving simulator to assess various outcomes related to speed, lateral control, and the identification of roadside objects. Employing a causal mediation framework, we hypothesized that perceived subjective fatigue would act as a mediator between having young infants and driving ability. Our findings revealed that participants in both groups—women with and without infants—maintained similar speeds and nearly identical lateral control during driving, despite reporting varying levels of subjective fatigue. However, women with infants exhibited a longer average response time (nearly half a second) and made more errors (twice as many) in identifying roadside objects. Although the indirect effect mediated by subjective fatigue explained some of these differences, a significant portion remained unexplained. This suggests that additional factors not considered in our study may contribute to the association between having young infants and diminished driving performance. Raising self-awareness of the perils of persistent fatigue may help to reduce driving crashes. • Mothers with infant children experience persistent fatigue. • This study assessed the driving abilities of two groups of mothers—with or without infants—using a driving simulator. • Mothers with infant children had slower reaction times and twice the errors in a secondary task, but similar speed and control. • Subjective fatigue partially mediated the differences in driving performance, but other unidentified factors may also play a role. • Raising awareness among new parents about the risks of persistent fatigue may help prevent driving-related incidents.