The usefulness of personal automobile availability in travel behaviour analyses as an alternative to the more familiar automobile-ownership approach is discussed. A measure of automobile availability for an individual based over a longer period of time (an average situation) rather than a person's actual access to the automobile at a specific time is offered. Four versions of the proposed definition of automobile availability are formulated and their performance is studied by examining the relationship between automobile availability and modal split. This is done by using data sets from Baltimore and the KONTIV data sets from Germany. Results of this analysis give preference to a simple three-level stratification automobile (never/sometimes/always) available in defining automobile availability for its apparent application in travel demand and policy analyses.
Abstract