Transport Affordability and Automobile Debt in the United States

Rising transportation costs have sparked widespread concern, with media headlines questioning whether the era of inexpensive automobility is over. Yet existing analyses often rely on sticker prices and aggregated sales data, failing to account for the full range of ownership costs such as insurance, fuel, and debt payments. This study bridges that gap by examining transportation affordability and “forced car ownership”—low-income households incurring high automobile costs due to limited alternatives. Using data from the U.S. Consumer Expenditure Survey from 1984 to 2023, we analyze trends in transportation expenditures, debt, and affordability using descriptive statistics, ordinary least squares (OLS), and binary logistic regression. Our findings reveal that while transportation expenditures have increased in nominal terms, real expenditures have remained relatively stable, and transportation costs as a share of household expenditures have declined since the 1980s. However, significant disparities persist. Low-income households, Black households, and households with multiple vehicles face disproportionate transportation cost burdens, with debt playing a critical role. Households in the bottom income deciles devote significantly higher shares of income to transportation, often driven by auto loans. Regional and demographic variations highlight structural inequities, with rural households and Southerners incurring higher absolute debt levels. These results underscore the inadequacy of existing affordability thresholds and the need for more comprehensive metrics that account for debt. By identifying the determinants of forced car ownership and its uneven distribution, this study offers policy-relevant insights into where transportation affordability initiatives should be targeted, and for whom.