Dr. Steven Spears' current research focuses on understanding how attitudes, perceptions, and habits affect transportation choices, and how these psychological factors interact with urban design to influence travel behavior and physical activity. He is particularly interested in how travel and residential location preferences evolve over time, and how they respond to changes in the built environment, life stage, and social support.

Since 2011, they have collaborated on the Neighborhood Travel and Activity Study (NTAS). The NTAS is the first experimental-control longitudinal study of a major transportation investment in California, and one of very few evaluations of this type conducted nationwide. It examines travel behavior dynamics and physical activity change associated with the opening of the Exposition light rail line in a largely low-income, minority community in south Los Angeles.