Exploring the Unnoticed: An Analysis of Voluntary and Involuntary Carless Households in California

Approximately 10.5 million of US households do not own cars. These households, who are often forgotten in transportation policy discussions, can be organized into two groups: voluntary and involuntary carless households. Understanding why some households decided to voluntarily forgo cars could inform policies to reduce the dependency on cars and reduce greenhouse gas emissions but understanding the plight of households who do not have access to cars is no less important as these households are at greater risk of social exclusion. Unfortunately, the knowledge of carless households is very limited so the purpose of this paper is to fill this gap. Using simple statistical tests and logit models, the authors analyze data from the 2012 California Household Travel Survey (CHTS) to better understand the characteristics of voluntary and involuntary carless households and to assess the effects of various socio-economic, residential, and land use variables on the likelihood to be carless (voluntarily or not). The authors' results show that voluntary carless households are more likely to have a higher average household income, a better education, a higher number of employed members, and a lower number of children than their involuntary counterparts. The authors' binary logit models emphasize the importance of land use diversity (via the land use entropy index) and of good transit service to help households voluntarily forgo their vehicles and downplay the impact of population density and pedestrian- friendly facilities.