AUTHOR=An Chengyuan , Shen Jiawei TITLE=Assessing the impact of Mobility-as-a-Service (MaaS) on sustainable urban travel behaviors: a systematic literature review JOURNAL=Frontiers in Sustainable Cities VOLUME=Volume 7 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/sustainable-cities/articles/10.3389/frsc.2025.1645488 DOI=10.3389/frsc.2025.1645488 ISSN=2624-9634 ABSTRACT=Mobility-as-a-Service (MaaS) is widely promoted as a way to reduce car dependency and encourage sustainable urban mobility, yet its actual environmental contribution remains unclear. This article presents a systematic literature review of 85 studies conducted in line with PRISMA guidelines to identify and analyze the elements within the MaaS ecosystem that influence sustainable travel behaviors. The evidence base spans multiple disciplines including psychology and behavioral sciences, sustainable development, urban planning, and transportation engineering, with most studies adopting cross-sectional survey approaches rather than examining longitudinal behavioral change or multimodal system integration. Findings show that adoption is consistently driven by convenience, affordability, technological appeal, and service reliability, while explicit sustainability motivations play a secondary role. Public transport integration, pricing structures that favor low-emission modes, and targeted subsidies for disadvantaged groups are linked with positive sustainability outcomes, whereas shared mobility services such as bike-sharing, e-scooters, and ride-hailing often substitute for existing low-emission modes rather than replacing private cars. Moreover, MaaS bundles that include car-based services can unintentionally stimulate car use, showing that measures designed to encourage adoption may work against sustainability goals. To address these challenges, the paper develops a conceptual framework that illustrates how governance arrangements, economic incentives, service design choices, and user engagement strategies interact to shape both platform uptake and environmental impacts. This framework emphasizes that adoption and sustainability are driven by different mechanisms and often work against each other, which highlighting the need for coordination to ensure that MaaS strengthens, rather than undermines, transitions toward sustainable urban mobility.