Guo studies individuals’ travel behavior and explores innovative ways to influence that decision-making process to produce better social outcomes such as reduced congestion and carbon emissions. The (dis)connection between government regulations, market forces, and consumer preferences is the focus of his research. Guo has conducted empirical work on transfer behavior in Boston, metro map design in London, parking in New York, and pedestrian environments in Hong Kong. His work has been covered by The New York Times, Wall Street Journal, BBC, The Economist, and others.