Diffusion of alternative fuel vehicles is both enabled and constrained by the interplay of powerful positive feedbacks arising from scale and scope economies, R&D, learning by doing, driver experience, word of mouth, and complementary resources such as fueling infrastructure. This poster describes an initial modeling effort focusing on the co-evolutionary dynamics between vehicle demand and fueling infrastructure. The model simulates both dynamically and spatially the interplay between consumer vehicle purchases and driving behavior and the development of a supporting refueling infrastructure. We reveal the formation of adoption clusters in urban areas as an important mechanism for early adoption, while, on the other hand, these local clusters are also an impediment to large-scale and sustained market formation. Expanding the model boundary to include other relevant dynamics, which would slow the technology diffusion, would enhance our ability to assess various transition strategies and policies.