The influence of spatial and household characteristics on household transportation costs

It is widely understood that location affects the cost of housing. Until now, the influence of location on household transportation costs has remained elusive, despite transportation costs being the second highest household expense. The Center for Neighborhood Technology (CNT) has developed a model that relates spatial and household variables to auto ownership, auto use, and transit use. A cost is then applied to each of these components to calculate the average household transportation cost for a neighborhood. This paper will focus on the multi-dimensional regression analysis used to relate the independent spatial variables (household density, block size, access to transit and employment, among others) and independent household variables (income, size, workers per household) to the three dependent variables (auto ownership, auto use, transit use). This model is used to estimate the transportation cost variation for a typical household in metropolitan areas, as featured on the website http://htaindex.cnt.org. This paper shows that variation in household transportation cost is related more strongly to the characteristics of a neighborhood than household. It is important to examine this phenomenon at small geographic level, i.e. the neighborhood.