The promise, prospects, and public policy trade-offs related to second-generation biofuels in road transport were addressed in an executive session convened at The Henry Ford Museum in Dearborn, Michigan, on April 7 and 8, 2015. The workshop brought together twenty-eight of the world's leading experts from the fields of policy, science, and business for an intensive two-day session. This report is a summary of the main points and issues raised over the two days. Several fuel options exist to steeply reduce net carbon emissions from road transport. They include electricity and hydrogen produced from renewable sources and sustainable, low-carbon biofuels. However, none of these fuel options can presently compete with conventional fossil fuels, and in the short term marginal emission reductions appear easier to achieve through engine efficiency improvements, including partial electrification in the form of hybrid electric vehicles, and selected first-generation biofuels. One of the key challenges is therefore to attract continued investment in R&D to bring down the costs of alternative-fueled vehicles and low-carbon biofuels.