Catching the Next Big Wave

Abstract

The aging of American baby boomers creates various new policy contexts and problems. Depending on institutional preparedness and baby boomers’ behavior, the changing demand for transportation services by this group may be positive or negative. This potential change in demand is described through an analysis of individual longitudinal histories over a long period (1989 to 2003) that explores the effects of personal changes (e.g., entry to and exit from the labor force), household changes (e.g., relocation and dissolution), and changes in land use characteristics. The Puget Sound Transportation Panel (PSTP)—a record of approximately 20,000 travel diaries of Seattle residents, each of whom provided 2-day reports for 10 repeated contacts (waves)—was used. Within-household dynamics and the effect of within-household change on individual and household behavior are studied. Focus groups are used to extract behavioral themes, latent class cluster analysis is used to identify groups of behavior, and an array of regression models of change is used to identify the key determinants that underlie behavioral dynamics. Findings include a need to focus on employment, heterogeneity in land use impact, and the significant effect of household composition. Together, the findings imply the need for models that can handle more diverse behavior and the need to accommodate employment status and within-household demographics in forecasting models.