The impact of public bike-sharing systems on mobility patterns: Generating or replacing trips?

Abstract

Bike-sharing systems allow occasional and regular users to travel by replacing other transport modes for the same trip or generating a new journey. Our research assesses the demand for Lisbon’s public dock-based bike-sharing system (BSS), named GIRA. This paper aims to identify the determinant factors that influence the potential of the BSS to generate new trips or replace previous modes using a conditional logit model based on a survey of 3112 BSS users. The survey results indicate that GIRA generated approximately 20% of the BSS trips, i.e., they would not have been realized if GIRA did not exist. The remaining BSS trips replaced other motorized (55%) and non-motorized (25%) trips. The main determinants explaining a higher likelihood of replacing different modes are having a yearly GIRA pass and a bike-sharing station within a 5-min walk. In contrast, regular car users are more likely to generate new trips, suggesting they use bike-sharing for recreational purposes. The findings provide policymakers with an assessment of determinants which may influence bike-sharing users to generate or replace trips from other modes and, consequently, define policies to potentially increase bike-sharing.