Alternative Measure of Household Structure and Stage in Life Cycle for Transport Modeling

A new concept in describing the structure of households is introduced. The average age of the household, as well as its relationship to the age of the individual, is shown to have some interesting and consistent properties that provide greater insight into the structure of households, particularly as an individual grows older. The relationships between age of the individual and average age and size of the household are shown to provide extra information to that contained in more conventional descriptive measures of household structure. In addition, with a model of trip generation based on chi-square automatic interaction detection, the average age of the household, along with its relationship to the age of the individual, is shown to be a more significant predictor of daily trip rates than some more conventional measures of household structure. It is shown that despite its computational simplicity, the new variable has promise in describing household structure and changes in life cycle and that further investigation of the properties of the variable should be undertaken.