Modal shift mechanism in the transition period from bicycle user to automobile user

As motorization spreads worldwide, concern is growing about the adverse effect of automobiles on energy resources and global environmental problems. A way to alleviate excessive dependency on automobiles is to promote bicycle transportation. However, it is difficult to increase bicycle usage except in some European countries, such as the Netherlands. In Japan the bicycle is commonly used from childhood through high school, but a rapid shift to the automobile takes place at college age. College students were surveyed by questionnaire on their bicycle use patterns and automobile ownership, along with bicycle use in their hometowns. The statistical analysis shows various relationships among population size of hometowns, regional characteristics, individual favoritism toward bicycles, financial condition, and so on. A clear difference was found between two groups of hometown regions for present bicycle usage patterns: those from large metropolitan areas and those from smaller regions. The transportation systems in cities and different population sizes influence bicycle use and favoritism toward bicycles, which in turn affects the present bicycle use level. Finally, the study reveals four factors that affect the modal shift froth-bicycle user to automobile user during the college-age period: physical environment, financial aspects, past experience, and favoritism toward bicycle use. These factors should be incorporated in designing bicycle transportation policy in urban areas.