An accurate estimation of household transportation costs related to a household location can be elusive. Current definition of affordability, which considers only housing costs, and is outmoded in a world where urban regions have spread so far outward that transportation costs have grown dramatically just to carry out the most mundane household errands and trips. Transportation costs are driven by location, and its intrinsic efficiency, as a result, the expense inherent to a housing choice location should be available before a household decides where to live. CNT has been developing tools to allow for this transparency so that households can fully understand the majority of costs involved in this geographic decision. CNT’s model for household transportation cost relates spatial and household variables to auto ownership, auto and transit use, a new formulation of this model has been created using a more simple and transparent formulation. The cost applied to each of these components to calculate the average household transportation cost for a neighborhood has also been updates. With more recent data sets from the American Community Survey and the Longitudinal Employer-Household Dynamics of the US Census, and others, there is an opportunity to update this work. This paper will focus on the multi-dimensional regression analysis used to relate the independent spatial (household density, block size, access to transit and employment, etc.) and household variables (income, size and workers per household) to the three dependent variables (auto ownership, auto and transit use). This model is used to estimate the transportation cost variation for a typical household in metropolitan areas, as featured on the website where the household variables have been fixed so as to allow for better understanding of spatial variation of affordability. CNT will also present this new formulation of average household transportation cost model and its relationship to the build environment .