Understanding the influence of fare reduction on public transport adoption: A study of Lisbon, Portugal

Abstract

In Lisbon, a fare reduction policy was implemented with the stated aim of attracting passengers to public transport while combating the negative externalities associated with car usage. However, no external assessment has yet gauged whether fare reduction effectively influenced public transport adoption. This paper evaluates the impact of fare reduction on public transport pass purchasing behavior as a proxy for public transport adoption and overall ridership. It employs a Random Forest machine learning model to explore the factors influencing pass purchasing and the heterogeneity of preferences among different groups. Primary data comes from a survey of over 1,000 Lisbon residents on transport expenditures and daily travel patterns. The findings reveal that fare reduction has a positive, yet limited, effect on public transport pass purchasing. Of those who did not previously purchase a pass, 27% started buying a Lisbon Navegante pass after the reform. Moreover, beyond potential savings, demographic characteristics like age, income, and gender, as well as behavioral patterns such as previous modal choice, significantly affect the likelihood of purchasing a public transport pass. While acknowledging the positive impact of fare reduction, the paper argues that fare reduction alone is unlikely to drive significant public transport adoption or a meaningful shift away from car use in Lisbon. It underscores the need for policymakers and urban planners to consider a broader spectrum of factors that shape travelers’ preferences and behavior.