Improving the understanding of mobility in cross‑border areas using a pooled travel survey

Understanding mobility behaviour in cross-border regions is a major challenge for transport policies and the wellbeing of people living near national borders. However, the available relevant information is often limited to a collection of unharmonized national sources. To overcome this limitation, we propose a methodology for building a pooled travel survey, by merging microdata from travel surveys conducted independently in different cross-border areas of the same cross-border region. Anchored in the Luxembourg functional cross-border region as a study area, this paper provides a general, ready-to-use harmonization methodology for pooling travel surveys. It critically discusses the resulting harmonized values of standard daily mobility indicators in regard to the specificities of the study area. Lastly, it shows that the values for the proportions of trip purposes computed with the pooled survey exhibit substantial differences from values obtained using only local travel surveys (up to 6 percentage points, and up to 33 per cent in the total number of trips). This illustrates the added value of a pooled travel survey compared with an unharmonized collection of local surveys.