Layering and parallel policy making - Complementary concepts for understanding implementation challenges related to sustainable mobility

This paper is focused on implementation challenges related to the integration of sustainable mobility in strategic local/regional land use and transport planning. The work was based on a case study of Stockholm, Sweden, focusing on four current plans and strategies of key importance for sustainable mobility. We identify and discuss implementation challenges related to sustainable mobility using a theoretical framework from the policy integration literature, with a focus on the dimensions of "layering", "drift" and "exhaustion" (Rayner & Howlett 2009). The empirical analysis led us to identify a complementary dimension which we call 'Parallel policy making'. The parallel policy making reflects a fundamental lack of integration of sustainable mobility in policies and plans of strategic importance, which hinders effective policy integration. Altogether, we conclude that a better insight into the practice of parallel policy making is crucial for development of more effective implementation strategies for sustainable mobility in Stockholm and elsewhere.