How carsharing services in residential housing impacts modal split and car usage – a multi-method investigation including legal challenges
Authors: Reindl Andrea , Graf Philipp , Knapp David , Schildorfer Wolfgang 
Published: June 2024

This study investigates the complex interplay between environmental concerns, urban mobility challenges, and legal intricacies associated with car ownership with a focus on Austria, Germany, and Switzerland. Carsharing (CS) emerges as a key element in transport systems, particularly in residential areas, aiming to reduce car dependency, reduce parking spaces, promote increased public transport usage, and reducing traffic congestion.The study explores whether CS induces a modal shift, how many cars can be replaced with a CS-vehicle, if developers can save parking spaces and thus construction costs through CS services, and what the legal landscape for parking and CS is in Austria. The research uses a multimethod approach, including a systematic literature review, semi-structured interviews, desktop research on existing carsharing projects in residential housing, and an examination of legislative aspects in Austria.Findings suggest that around 25% of analysed papers explore the connection between CS and housing. Interviews highlight key enablers for CS, including good public transport access, strategic placement of CS hubs, and the availability of e-cars. Experts specializing in the carsharing field suggest on average 12 cars can be replaced by one CS vehicle. Projects implemented in Austria, Switzerland, and Germany, where CS costs are shared among tenants or mobility fees are incorporated into rent, indicate the viability of this approach. Additionally, projects in Switzerland that regulate car ownership in lease contracts suggest the potential for reducing parking spaces by offering adequate alternative mobility options. CS is explicitly addressed only in Vienna's garage law, permitting the reduction of mandatory parking spaces. In other Austrian federal states, it is generally subject to case-by-case evaluations.Therefore, carsharing is integrated into housing developments, but faces challenges like parking limitations and legal complexities (Caruso, 2023). Austria's complex legal landscape, governed by individual states, adds intricacies to car-sharing feasibility in residential complexes. Navigating this legal terrain to realize practical mobility solutions is challenging due to limited documentation on actual projects. The study explores whether carsharing induces a modal shift. Additionally, it investigates whether developers can save parking spaces and construction costs through carsharing services, evaluating literature and practical experiences for potential reductions in parking spaces ​(Caruso 2023)​. To address the research questions, a multimethod approach was employed. Initially, a systematic literature review was undertaken to investigate whether the implementation of car sharing in residential developments could induce a modal shift, reduce private car ownership, and consequently decrease the required number of parking spaces. Using a defined search string, 188 results were initially identified, and after a rigorous elimination process, 45 papers remained for in-depth analysis. To gain insights into the practical implementation of mobility in housing, semi-structured interviews were conducted with 13 experts, project managers, funding experts, and residential developers and operators. Additionally, desktop research on existing housing projects was carried out, evaluating currently more than 25 projects in Austria, Germany and Switzerland. The legislative aspects, involving parking space regulations, mobility contracts and building codes in Austria's nine federal states, were examined through desk research and interviews, comparing them with regulations in Germany and Switzerland. This multimethod approach allowed for a practical exploration of the research questions, by complementing all results of literature, project research, interviews, and legislative background within a master matrix. The study, concluding in January 2024, provides findings from its literature review, revealing that around 25% of the analysed papers explore the connection between carsharing and housing. Preliminary findings from interviews, emphasize that key enablers for carsharing include good public transport access and city bicycle networks, strategically placed carsharing hubs with recognizable branding, and the availability of e-cars for mobility assurance. This study gives a policy overview of the current state in Austria and lays a foundation for future research.