The national travel survey and other data sources: An assessment of data quality and data sources in the context of the Norwegian urban growth agreements

The Norwegian zero-growth policy aims to ensure that any increases in urban mobility due to population growth are absorbed by public transport, cycling, or walking, rather than by an increase in car traffic. To enforce this policy, the government has introduced city growth agreements as its primary policy instrument. Compliance with this policy is monitored using two main data sources: the Byindeks (City Index), which aggregates vehicle counts, and the National Travel Survey, which estimates vehicle kilometers driven by the population. These data sources measure different aspects of traffic and often provide conflicting indications of traffic trends. This report examines the discrepancies between these data sources and explores potential strategies to address these inconsistencies.