Inter-temporal analysis of household car and motorcycle ownership behaviors

This study investigates household car and motorcycle ownership in Nagoya metropolitan area of Japan. Bivariate ordered pro- bit models of household vehicle ownership were developed using the data from the case study area at three time points, 1981, 1991, and 2001. The accessibility that is generally known to be correlated with vehicle ownership decisions is incorporated as an input for the proposed vehicle ownership model to investigate the potential relationship between them. The mode choice models for the area were first estimated to quantify the accessibility indexes that were later integrated into the vehicle ownership models. Inter-temporal comparison and temporal transferability analysis were conducted. Some of the major findings suggest: 1) that age and gender differences have become less important in modal choices and car ownership as motorization proceeds; 2) that the accessibility seems to have a significant correlation with vehicle ownership; 3) that car and motorcycle ownership may not be independent and may have a complementary relationship; and 4) that the deep insights concerning the model selection are obtained from the viewpoints of the temporal transferability.