Continuous urban areas enhance connectivity, reduce travel needs and car dependency, and facilitate the use of non-motorised transport modes, such as biking and walking. In addition to environmental improvements, continuous urban areas may induce energy savings, reduce maintenance costs for energy and transport systems, improve the quality of life through local services and jobs and allow efficient infrastructure investments (OECD, 2012). Overall, the findings of the study suggest that instruments aiming at increasing continuity and reducing population density are worth considering in the policy mix used to avoid further air quality degradation by the expansion of urban areas in Europe.