The effects of highways on transforming human society and promoting population change have been investigated in several disciplines, including geography, sociology, economics, and planning. Currently, the primary highway construction activity in the nation is highway expansion; however, this expansion has not been the focus of much of the existing literature. This research examines the role that highway expansion plays in the process of population change. Specifically, this research proposes an integrated spatial regression approach to study the impacts of highway expansion on population change in the 1980s and 1990s in Wisconsin at the minor civil division level. The integrated approach thoroughly considers the factors that influence population change, appropriately examines the spatial variations of their impacts, simultaneously incorporates spatial lag and spatial error dependence, and systematically selects the optimal neighborhood structure. The findings suggest that the impacts of highway expansion on population change differ across rural, suburban, and urban areas: There are only indirect effects in rural areas, both direct and indirect effects in suburban areas, and no statistically significant effects in urban areas. Overall, highway expansion serves as a facilitator of population change within the framework of growth pole theory and location theory. (Contains 3 figures, 4 tables and 10 footnotes.)