The thesis analyzes the conditions for biogas in the Swedish transport sector. Biogas can contribute to the achievement of Sweden’s ambitious targets of decreased emissions of greenhouse gases and an increased share of renewables in the transport sector, a sector that encompasses the major challenges in the phase-out of fossil fuels. Biogas development has stagnated during recent years and there are several factors that have contributed to this. The use of biogas in transport has developed in niches strongly affected by policy instruments and in this thesis, the progress is understood as a policy-driven systemic transition. Biogas has (started to) become established at the regime level and has begun to replace fossil fuels. The major obstacles for continued biogas development are found to be the stagnated vehicle gas demand, the low predictability of Swedish policy instruments, and electric car development. Moreover, the current prolonged period of low oil prices has also contributed to a lack of top-down pressure. A large share of the cheap and easily accessible feedstock for conventional biogas production is already utilized and an increased use of vehicle gas could enable a commercial introduction of forest-derived methane. However, the technologies to produce forest-derived methane are still not commercial, although there are industrial actors with technological know-how. Future biogas development depends on how the policy framework develops. Policy makers should consider the dynamics of biogas as a young sociotechnical system where different system fronts develop at a varying pace. Currently the demand side is lagging behind. However, it is necessary to maintain predictable policy support throughout the entire biogas value chain, since the system fronts that lag can vary over time. The low predictability of Swedish policy instruments indicates that policy makers should exercise care in their design to create a more robust policy framework moving forward. / <p>QC 20170508</p>