Travel time budgets and the potential to replace travel by car in urban regions: A case study from Finland

A shift towards sustainable modes of transport (walking, cycling, and public transport) is urgently needed to reduce the negative externalities of private car use. Whereas active travel is a feasible alternative for relatively short distances, public transport can substitute for a larger share of car use. City regions are often seen as the main targets for this mode shift given the availability of public transport options and the proximity of services. In this work, we provide insights into the quantitative potential to shift car travel towards sustainable modes in small and medium-sized cities. We investigate the potential to replace car use as driver or passenger on home-based round trips according to threshold-based travel time criteria. The analysis is based on national travel survey data for Finland’s city regions and counterfactual travel times. We investigate three scenarios with varying active travel and public transport travel time budgets, walking and cycling speeds, and maximum public transport trip durations. In the baseline scenario, approximately 35% of round trips and 12% of car mileage could be shifted from private cars towards sustainable modes. In the maximum potential scenario, the mode shift potential increases to nearly 47% and 21% of round trips and car mileage, respectively. In the e-bike scenario, the mode shift potential exists for 39% of round trips. Our results suggest that there is a sizeable potential to replace car travel in urban regions, and this shift could be achieved with modest increases in travel time budgets.