Trip chain characteristics and situational factors influencing private car mode choices – A survey study in two Finnish urban areas

• Trip complexity influences utilitarian and non-utilitarian factors. • Trip purposes influence situational factors behind private car use. • Errand trips are associated with habitual car use. Human mobility is often characterized by trip chains with multiple destinations. However, the reasons behind mode choices have been mostly studied in single-purpose travel contexts. To address this gap, we examine how trip chain length, complexity (number of trip legs), and purposes are linked to situational factors influencing the decision to use a private car (i.e., context-dependent considerations that affect travel decisions, such as the need to save time, avoid bad weather, or be able to relax). Data was collected through a survey where participants described a recent private car trip chain, including items about trip purposes, the number of trips and trip legs, trip length, and the importance of various situational factors on mode choice decision. The survey was conducted in two major urban areas in Finland, yielding 731 valid responses. The results of a regression analysis show that all examined trip chain characteristics impact on the prevalence of different situational factors. Leisure being a trip purpose was associated with non-utilitarian factors influencing car use, and errands and commuting with both utilitarian and non-utilitarian factors. Trips involving errands appeared more habitual than trips for other purposes. Furthermore, complexity was not only associated with utilitarian factors, but also non-utilitarian. The findings suggest that trip chain complexity and purposes should be considered by practitioners and policymakers in sustainable mobility campaigns, passenger information systems that account for trip chain characteristics should be developed, and targeted interventions to reduce habitual car use, especially for errands, should be created.