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Collecting data on travel behaviour - a new survey approach

Collecting data on travel behaviour - a new survey approach

The Institute for Transport Planning and Systems (IVT) explores a new survey approach for analyzing additional travel demand brought about by changes in daily travel conditions. The respondents complete a five-day travel diary, from which one day is selected for further analysis. The conditions of that day are changed using predefined heuristics based on the household characteristics, thus modifying the generalized costs (the elements that constitute the disutility of travelling) of the reported schedule. The households are faced with these scenarios in face-to-face interviews. All household members are asked to state how the implied changes would affect their activity scheduling.

Induced traffic, a phenomenon that is defined as changes in demand for transport services generated by changing travel conditions, has been a topic of ongoing research for many years. The main focus has often been the analysis of measures bringing about such changes in generalized costs. Previous studies have focused on specific and localized measures, such as the construction of new roads or rail lines in given corridors, and the assessment of their side effects. This study attempts to model effects on several indicators of traffic generation, which are: the propensity of participating in out-of-home activities (that is, to be mobile on a given day), the number of trips and activities carried out, and the resulting time spent outside of the home location.

The work is part of a research project funded by the Swiss Association of Transportation Engineers (SVI). The abovementioned effects are assessed on a disaggregate scale with a so-called stated adaptation survey. A sample of respondents was recruited for participation in the study, which consists of two parts, the first being a five-day travel diary. Here, the respondents are given the choice of a traditional pen-and-paper or an on-line questionnaire. For the second part, the surrounding conditions of one of the five days’ travel are changed. The rules used are based on the household characteristics and the activities reported by the respondents. This results in significant changes to the constraints of the reported schedule and thus provides an impulse for changing behavior. The times for traveling to certain activities are modified, thus creating hypothetical scenarios to which the respondents need to react. The households are faced with these changes in face-to-face interviews, where all household members are asked to state the likely effects that the implied changes would have on their schedule on the specified day. These interviews are conducted by the means of a specifically designed software program, on laptop computers at the households’ homes.

The data will allow the computation of detailed models of activity scheduling. The results are expected to reflect the effects of the various changes in generalized costs on the indicators mentioned above. The model results will be applied to generate improved utility functions for daily schedules in MATSim, the agent-based micro-simulation software developed at the Institute for Transport Planning and Systems (IVT) at ETH Zurich and the TU Berlin. The application will allow the computation of aggregated effects of measures changing generalized costs, as well as their repercussions on the transport system.

Claude Weis

Weis, Claude; Dobler, Christoph; Axhausen, Kay W. (2010): An Interactive Stated Adaptation Survey of Activity Scheduling Decisions. Zürich: Arbeitsberichte Verkehrs- und Raumplanung, 637, IVT, ETH Zürich. PDF