The analysis of the factors determining changes in travel behavior on the individual (or individual household) level requires information on the behavior of individuals over time. Such "transport" panel surveys are rarely available, particularly for a sufficiently long time period to examine such changes more than cursorily. For the United Kingdom, none exists for other than limited regions. However, the ongoing British Household Panel Survey (BHPS), begun in 1991, provides some information related to transport--specifically, household car ownership--as well as information on the economic and sociodemographic characteristics of the households surveyed. BHPS data for 1993 to 1996 are used to analyze car ownership and the factors determining car ownership decisions on an individual household level. As far as is known, this has not yet been done in any systematic manner. The relationship between car ownership, income, and sociodemographic factors such as household composition, residential location, and population density (persons per hectare in the local authority district in which the household resides) is investigated. Both descriptive statistical measures and formal modeling approaches, based on dynamic discrete choice models and panel data econometric techniques, are used.