Research Publications

With the introduction of a number of small and electric-powered vehicles into the marketplace, the variety of energy efficient choices available for meeting household transportation needs has increased dramatically. However, due to the variability inherent in household travel, an efficient vehicle with reduced capability may not be able to meet the requirements of every trip in terms of range, or passenger and cargo capacities. In order to understand the potential for these new vehicles to contribute to actual energy savings, it is necessary to consider the travel requirements of households over a period spanning months or years. This presentation describes a method for collecting long-term household travel requirement data, and presents the results of a pilot test involving several households in the vicinity of Ann Arbor, Michigan. Traditional travel surveys collect details about individual trips, which is not practical for a period of more than a few days. GPS instrumentation can be used over longer time periods, but it is difficult to discern important information such as trip purpose, or the number of passengers. For this research, an online survey was developed which asks respondents to report their typical travel according to the purpose of the activity being conducted. For each activity, "fuzzy" descriptions are then collected, such as the range of possible activity times, or the likelihood that it will be conducted on a certain day, or at a certain location. It was hypothesized that for long time periods, respondents will be able to probabilistically report typical travel more accurately than they can recall individual trip details. Based on the pilot survey results, a travel scheduling model was used to simulate whether various fleets of efficient vehicles could be adopted by the household. In cases where a vehicle could not satisfy every travel requirement, a reliability factor is reported.