THE EFFECTS AND CHALLENGES OF MUNICIPALITY INITIATIVE FOR POLICY DIFFUSION OF STREET DESIGN TOWARD ENHANCING LIVABILITY —THE CASE STUDY OF NATIONAL ASSOCIATION OF CITY TRANSPORTATION OFFICIALS IN THE U.S.—

<p> The research targeted the National Association of City Transportation Officials (NACTO) in the U. S. and the Global Designing Cities Initiative (GDCI), which have built domestic and international initiatives centered on the municipality level. They aimed to diffuse street design measures toward livable city goals and have expanded member cities in recent years. The research conducted 1) material surveys related to the initiative activities, publications, and programs, 2) interviews with a director and an officer of a member organization, and 3) aggregation of statistics on the safety and modal share of member cities compared to the national trend. The result clarified the characteristics of the internal function of the association and its contribution to design and engineering diffusion to member cities, especially by enabling municipalities to apply context-sensitive design and metrics for them. As a factor that helped the expansion of domestic and international cooperation, the functional similarities with the ‘Transnational Municipal Network’ in the European region have been confirmed.</p><p> Through the findings gained in the diffusion of street design measures aimed at enhancing the livability by NACTO and GDCI, the significance of the network among domestic and international municipalities was proved to build the capacity of the local department in charge and to accelerate pilot projects. Meanwhile, it indicated challenges from the perspective of the achievement status of outcomes set by NACTO, such as the modal shift to public transportation. Considering the spillover effect of street network conditions surrounding the target area, it is crucial to maximize the impact by implementing design changes to the urban environment through a geographical concentration of the collaborative-policy member organization.</p>