Introduction<lb>217<lb>Abstract This chapter studies housing and transport budgets in the Greater Paris Region,<lb>thereby shedding light on household residential strategies. The evaluation method<lb>combines the use of a travel survey and of transit and road traffic assignment models,<lb>completed by databases on prices and household expenses when necessary.<lb>The analysis leads to two main findings. First, households allow on average for<lb>a relatively constant share of their income to housing, which decreases with income.<lb>Home size increases with distance to CBD, reflecting lower prices. However, household<lb>size rises at the same time, and all in all the average surface area per person varies<lb>little with location.<lb>Secondly, the average transportation expense ratio grows significantly with<lb>distance to the center of Paris. This mirrors both an increased motorization and a<lb>more intensive use of the car, which enable households to travel longer distances for<lb>identical daily travel times, but at the price of dangerously high transport costs.<lb>Once again, lower-income brackets average higher burdens.<lb>These various findings lead me to the following hypothesis, that the household<lb>primary objective is to reach a certain level of “housing comfort” (33 m2 per person<lb>or so). Transport serves as a variable of adaptation to reach this goal, inasmuch as<lb>households select the best location in a certain radius around the workplaces of<lb>household members, given a target housing budget but whatever the transport cost.<lb>The radius is set in terms of travel time, hence the usefulness, and yet a “curse” at<lb>the same time, of the car.