Many modern transportation systems rely on efficient allocation of resources across large networks with complex spatial and temporal considerations. This already challenging task is often further complicated by the presence multiple interacting decision-makers and stakeholders. Our research aims to develop methods for analysis, forecasting and effective decision-making in these complex systems. We combine tools from optimization, game theory, and machine learning with increasingly available data on transportation operations and decisions. Our current projects tackle problems in aviation, urban transit and ride sharing, maritme transportation, and high-speed rail. Click on the headings below for details of selected projects in various application areas.