In France, the transportation sector is a major contributor to greenhouse gas emissions and air pollution. A large portion of these negative externalities are caused by road transport, due to the movement of people and goods. As a result, the transition to low-carbon mobility is one of the main challenges of the Stratégie Nationale Bas-Carbone 2 (French National Low Carbon Strategy 2), which aims to achieve the complete decarbonization of surface transport by 2050. With the growing awareness of the need for sustainability, mobility systems must offer innovative solutions that are more respectful of the environment and capable of satisfying user needs. Modular Architecture Intermediate Vehicles (MIVs), which fall between the conventional bicycle and the private car, offer a combination of technical and functional flexibility. They are less polluting, more energy and space efficient, and more affordable than internal combustion vehicles, mainly used for short trips and urban logistics. However, MIVs are still not very present in our mobility ecosystems, and their emergence means that their deployment needs to be questioned beforehand, as the expected environmental, economic and land-use benefits remain hypothetical. Moreover, the lack of standardization of vehicles, traffic and parking rules, and their modular nature are all factors that are likely to influence their widespread adoption. As a result, these innovations are not limited to the simple development of products, but are part of a deep transformation of mobility service models, in which the co-creation of value between users, operators and local authorities becomes a central issue. Users can steer the service offering through a growing demand for personalization, while public authorities can influence their adoption by defining regulatory and incentive frameworks. This thesis provides an in-depth understanding of the socio-economic dynamics underlying the adoption, use and deployment of MIVs. It explores how these hybrid product-service innovations can sustainably transform mobility systems to support ecological transportation planning, and seeks to test the ability of modularity to foster their adoption. Three lines of research will be developed. First, we plan to challenge standard behavioral economics theories and develop an integrated framework to study interactions between the macro, meso, and micro dimensions of the ecosystem, capable of combining the effects of individual perceptions, public transport policies, and characteristics of the spatial and infrastructural environment. We then propose to empirically investigate the determinants of adoption and use of new product-service systems (PSS) based on MIVs. This analysis will be based on a multi-level theoretical framework, extensive data production, and the articulation of contingent valuation methods and stated preference surveys. Finally, we will assess the systemic impacts of the introduction of new MIV PSS in the mobility ecosystem by identifying and measuring the externalities associated with their deployment, in particular through multi-agent simulations. This thesis is characterized by its ambition to design a unified theoretical framework for assessing the adoption of mobility innovations, focusing on an emerging solution and its combination of micro-behavioral and macro-systemic explorations. It aims to enlighten public and private players on the strategic levers that can be activated, to encourage the adoption of mobilities likely to support a coherent and harmonious ecological transition in transportation.