Clay, Michael J. and Patricia L. Mokhtarian (2002) The Adoption and Consideration of Commute-Oriented Travel Alternatives. Institute of Transportation Studies, University of California, Davis, Research Report UCD-ITS-RR-02-04
The data analyzed in this study come from a fourteen-page self-administered survey mailed in May 1998 to 8,000 randomly selected households in three neighborhoods of the San Francisco Bay Area. Half of the total surveys were sent to an urban neighborhood of North San Francisco and the other half were divided evenly between the suburban cities of Concord and Pleasant Hill. These areas were chosen to represent the diverse lifestyles, land use patterns, and mobility options in the Bay Area.
These data were analyzed in several ways. First, descriptive information was obtained and presented. Next, using chi-square and t-tests, individual relationships were explored between the adoption/consideration of travel-related alternatives and the respondents' demographics, objective mobility, subjective mobility, relative desired mobility, travel liking, travel-related attitudes, and personality and lifestyle preferences. The final set of analyses deals with the travel-related alternatives as bundles rather than as individual measures.
In order to better understand how the travel-related alternatives interact with travel attitudes, demographics and the other variables in our analysis, the travel-related alternatives were grouped into bundles based on conceptual and empirical similarities. Two types of travel-related bundles are analyzed in this report. The first set consists of three bundles (travel maintaining/increasing, travel reducing, and major location/life change) that were created based on conceptual similarities between the alternatives' generalized costs and amount of lifestyle change associated with adopting them. The second set of bundles was created using factor analysis of the responses to identify groupings having a similar empirical pattern of responses. Eight bundles emerged from this second method.
It was hypothesized that people with a strong positive attitude toward travel, and who want to travel more than they are currently doing, are less likely to adopt or consider alternatives that will reduce or restrict their travel (and conversely for those with a strong negative attitude toward travel, and who want to travel less). This report presents evidence in support of these hypotheses.
In general the results were consistent with prior hypotheses, but a few unexpected relationships emerged. For example, adventure seekers and the family/community oriented appeared inclined to try the full range of travel-related alternatives, not just those supporting travel (in the former case) or reducing it (in the latter case). Ambiguous directions of causality were likely responsible for some unexpected results. While a given variable could generally be viewed as antecedent to consideration (and hence plausible as a cause), it could often be viewed as a cause or an effect in the case of adoption.
While further research is needed to clarify many of the complex relationships discussed in this report, the results presented here are useful in that they identify pairwise relationships between the respondents' characteristics (amount of travel, perception of travel, desire for travel, demographics, attitudes, liking of travel, and personality and lifestyle preferences) and the travel-related strategies that they have adopted and are considering.