Estimating Availability Effects in Travel Mode Choice Among E-bikes and Other Sustainable Mobility Services: Results of a Stated Portfolio Choice Experiment

Electric bikes are considered an important sustainable alternative to private cars. This transportation mode competes with other new mobility modes, such as Shared Mobility and Mobility as a Service (MaaS). Because these services may not always be available, people may face a variety of choice options in different cities/regions. Despite their relevance, most studies of e-bike mode choice do not consider these availability effects, which may bias estimated acceptance rates and market shares of e-bikes. This paper reports the formulation and estimation results of a discrete portfolio choice model incorporating the availability effects of other sustainable mobility services to explore individuals' willingness to buy pedelecs and speed pedelecs. We designed a stated portfolio choice experiment considering varying choice set composition, where Shared Mobility or/and MaaS may not be available. An error component logit model was formulated to analyze the availability effects. The knowledge we gained regarding the willingness to buy e-bikes in the presence or absence of motorized shared mobility options has major practical implications as some pilot studies have evidenced decreasing use of active modes once motorized shared mobility becomes conveniently available.