Workshop Synthesis: Catching Travel Behaviour at the Right Time: When and How to Collect Non-Routine Travel Patterns in Cross-sectional, and Longitudinal Data Collections

Accurately measuring travel behaviour is essential for understanding and forecasting mobility. While established methods exist for collecting routine travel data, best practices for measuring non-routine travel (like holidays or long-distance trips) and longitudinal data are less developed and often inconsistent. This paper presents the outcomes of a workshop held at the ISCTSC conference, where we discussed the right timing of surveys, the right duration to capture, and the best interval between waves. Effective data collection for non-routine travel must consider the right timing, such as covering holidays or entire years, and use either repeated measurements or extended sampling periods to reduce recall bias and capture variability. For longitudinal surveys, the interval between measurements must balance respondent burden, likelihood of behavioural change, and seasonal effects, with tailored recontact strategies and personalized communication. Overall, survey design must account for participant fatigue, memory limitations, and attrition risks to ensure data reliability and representativeness.