Temporal dependence in life trajectories and mobility decisions

It is increasingly realized that mobility decisions and choices such as residential choice, job/employment choice and travel choice need an integrated representation. Yet, in existing models, integration is limited to residential choice and travel choices. Moreover, behavioural models used to analyse these issues are static. Dynamics of these mobility decisions over time and also the relationship among decisions from different domains such as household changes are not incorporated in existing land use and transportation researches. In addition, empirical studies of time dependencies are also limited. In this regard, the paper investigates dynamics explicitly by looking into the changes, for example residential relocation towards moving up, moving down and no-change move; change in employment; and change in car ownership level; and the temporal relationship among these long-term mobility decisions and with household events like cohabitation, separation, childbirth, child’s home leaving and retirement. A Bayesian Belief Network approach is followed to investigate the underlying causal structure and learning the parameters. Data used for the analysis are collected from a retrospective survey in the Utrecht region of the Netherlands. The results suggest that very limited interdependencies among mobility decisions exist; only example is car acquisition and moving down. Time dependencies are also found in the analysis. The important findings, in this regard, are that birth of the first child has an advanced effect on moving up and car acquisition; cohabitation has a lagged effect on employer change; cohabitation has also a concurrent effect on moving up, car acquisition and employer change; divorce or separation has only a concurrent effect on moving down and car disposal.