An Innovative Method for Longitudinal Travel Data Collection: The MPN Netherlands Mobility Panel
Sascha Hoogendoorn-Lanser, KiM Netherlands Institute for Transport Policy Analysis, Nina Schaap, KiM Netherlands Institute for Transport Policy Analysis, Paul Van Beek, Goudappel Coffeng
The MPN Netherlands Mobility Panel is a longitudinal household panel aimed at determining how changes in personal/household characteristics and other factors result in changes in travel behavior. Setup is discussed and resulting data quality assessed
Life events such as moving house or having children may greatly influence travel behaviour. Socio-economic trends and developments, such as increasing Internet use or a financial crisis, also have impact on mobility choices. We would like to know with greater precision how these life events and trends influence travel patterns. Do people buy new transport vehicles as they start to have children, move closer to their work, or get older? What kind of impact do web applications such as Facebook have on mobility choices? How do the members of a family agree among themselves who may use the car and when? And how does the travel behaviour of individuals and households vary from day to day and from year to year? The MPN Netherlands Mobility Panel is a new and unique longitudinal household panel that is designed specifically to give insight into the short-run and long-run dynamics in travel behaviour of individuals and households, and to determine how changes in personal and household characteristics and other travel-related factors (e.g., changes in land-use) correlate with changes in travel behaviour.
In this paper, we put forward the MPN set-up including its objectives, data collection approach and sampling technique. Important contributions of the paper are the method applied to translate the MPN research objectives into requirements on the data collection approach, as well as the innovative design approach of the web-based diary.
Between September 2013 and November 2016, 2,500 Dutch households (i.e., all household members aged 12 and over) will be questioned yearly about their mobility and related topics. In this longitudinal study, detailed travel data is collected using a three-day self-completion location-based diary and multiple questionnaires are used to collect data on household and personal characteristics, transport-related aspects (such as use of ICT for shopping, working and leisure), vehicle availability, and changes in personal circumstances.
In designing the MPN travel diary, the authors aimed to optimally benefit from the state-of-the-art knowledge on diary design as well as the opportunities that a web-based approach provides. Using a web-based approach, respondent burden was reduced and the risk of errors and omissions in the data was lowered by implementing automatic checks on illogical or missing answers. The web-based questionnaires and the mobility diary were supplemented with a paper memory jogger, text message and email reminders, and telephonic and on-line assistance.
Identifying and explaining day-to-day variations in mobility (day-to-day variability or the difference between weekdays and weekend days) is one of the aims of the MPN, requiring a research period longer than one single day. However, with every additional data collection day, the risk of respondent fatigue and a decline in completeness and accurateness increases. This trade-off between completeness and reliability resulted in a data collection period of three consecutive days. A prospective research design and a memory jogger were chosen to prevent underreporting of short-distance, non-home-based or non-motorized trips, lack of trips details and rounding times (Wolf, 2003). Furthermore, the diary is setup location-based, as people are generally better at remembering in which activities they were engaged or where they were, than which trips they made (Stopher, 1992) and literature on travel surveys suggests that location-based journals provide the most accurate trip data (e.g., Behrens and Masaoe, 2009). Respondents are therefore asked to first fill out their locations and corresponding main activities, and to subsequently provide details about their trips and trip stages. An easy-to-understand visual overview of the day is shown while respondents enter their locations, which further helps to trigger peoples’ memories – a significant advantage of the chosen web-based approach.
The paper will describe in detail the setup of the MPN data collection techniques. In addition to the design aspects, we will assess how the setup of the MPN has influenced the quality of the data, in particular for those types of trips that are often under recorded in other travel surveys, such short-distance, non-home-based trips and non-motorized trips. The assessment of the MPN travel data will also include feedback from respondents obtained in in-depth face-to-face interviews that were held with a subsample of respondents in parallel to the first wave.
Behrens, R. and Masaoe, E. (2009). Towards improved travel diary survey instruments in African cities. Paper presented at the Southern African Transport Conference Pretoria.
Stopher, P.R. (1992). Use of an activity-based diary to collect household travel data. Transportation 19, 159-176.
Wolf, J., Oliviera, M. and Thompson, M. (2003). Impact of under-reporting on mileage and travel time estimates: results from global positioning system-enhanced household travel survey. Transportation Research Record 1854, 189-198.
Association for European Transport