Triggered by concerns on climate change and the security of energy supply, hydrogen has gained increasingly attention as an energy carrier, especially as a transport fuel. Against this background the study investigates the prospects and limits of pathways for hydrogen production, distribution and use in transport in comparison with other alternative fuels. Special emphasis will be put on the greenhouse gas emissions of the various fuel paths and the strategic question of an optimal allocation of renewable energy sources to the different pathways. The study contains a synopsis of current activities and priorities of future research work, followed by an analysis of driving forces and frame conditions. In a second phase, a comprehensive assessment of hydrogen technology chains will take place, incl. all stages from production via transport and distribution to the final end-use. In a third step, the various pathways will be compared from an energy system's point of view in order to identify interdependencies and synergies between the options that can be used to manage a transition phase to future sustainable fuel infrastructures in road transport.