How more data reinforces evidence-based transport policy in the Short and Long-Term: Evaluating a policy pilot in two Dutch cities

Data have played a role in urban mobility policymaking for decades. Especially since the emergence of big data, many researchers have shown how to advance data use to improve understanding transport policy effects, but there is hardly insight in how this is adopted in policy practice. This study aims to address this gap by answering two questions: (1) how is data currently embedded in urban mobility policy- and decision-making; and (2) what are the advantages and limitations of more data use in these processes? We chose two Dutch cities -Maastricht and Groningen-that were both involved in a national programme (BeterBenutten) that trialed (and funded) a more evidence-based policymaking approach.We did ten semistructured interviews with the people work in the mobility department and analyzed the twenty-one most relevant policy reports to understand how more data reinforces/impedes transport policymaking in practice. We found that data use differed in long-term and short-term policy cycles. In the long-term policy cycle, data was regarded as less important than political and societal trends and developments; in the short-term cycle, data played a major role in prompting traffic regulations and policy adjustments.Policy insights can be derived from this research on how data can be better embedded in policymaking practices (1) The support from national/regional level (i.e. BeterBenutten program): could provide extra opportunities for local governments to do ex-post policy assessments, which has been regarded as valuable resources for evidence-based decision-making by policymakers. (2) Survey data can still play a significant role in urban mobility planning by typically providing more insights in the 'why' of traveler behaviors than big data. (3) Transport policymakers need to strength their abilities in selecting suitable data (out of a much larger set) and having more (competent) personnel capacity to interpret data. (4) Promoting sustainable mobility is a strong driving force for the local governments to enhance data use.