In this article, the development of biogas for transport in the municipality of Linkoping, Sweden, is studied in order to contribute to a better understanding of the conditions for socio-technical transitions towards sustainability. Linkoping municipality, 1976 [kommunfullmaktige] Motion om utredning angaende eldrivna fordon. Dnr 1976.278. Using concepts from multi-level perspectives and sociotechnical perspectives on system builders, the study focuses on three time periods: During the first time period (1976-1994), a niche for biogas developed amongst dedicated actors in small networks representing energy and public transport within the municipality. That is, biogas was entirely connected to the vision of a 'green' public transport. Second, between the years of 1994 and 2001, the biogas producing company acted as a system builder and initiated a large-scale biogas production through close cooperation in networks with other actors. As a result, biogas reached a phase of technological maturity and also gained some support from national investment programs. Finally, from 2001 the expansion of biogas became clearer as the biogas production spread into a regional arena but also reached for new customers, like personal cars. Unforeseen spin-offs like the formation of new private companies and development of research were important results of the transition. Thereby, the transition is a move towards a new socio-technical regime. A conclusion from the study is that the development of biogas was highly influenced by national support and pressure, but was mainly driven by local actors system builders that could steer the processes and had endurance as well as capability to mobilize resources in order to fulfill their purposes. (C) 2014 Elsevier Ltd. All rights reserved.