My students and I study transportation, not as an end but as a means to social and economic activity, opportunity, and equity.  My research examines the varied benefits of travel, the often high costs, and the frequently unfair allocation of these benefits and costs.  The work focuses on transportation systems, travel behavior, and transportation planning and decision-making, and collectively shows how the social and economic benefits and costs of travel are inefficiently and inequitably distributed.

Topically, my research covers four broad areas, often through an equity lens: