Urbanization and Drivers for Dual Capital City: Assessment of Urban Planning Principles and Indicators for a ‘15-Minute City’

Cities, particularly megacities, face significant challenges in transitioning toward sustainability. Many countries have developed dual or multiple capitals for diverse purposes (e.g., political, administrative, economic, touristic, and cultural). Limited research exists on the ‘15-minute city’ (15-MC) concept, particularly in regions like Middle East and North Africa (MENA region). This study evaluates the application of the ‘15-MC’ concept globally and regionally to derive Urban Planning Principles (UPPs) and indicators for livability and accessibility. Using a theoretical framework supported by site visits and quantitative assessments, the research examines two districts in the NAC as case studies. Key UPPs (e.g., proximity to services, mixed-use development, public transport, green spaces, community engagement, local economy, and sustainability) were evaluated along with walkability scores, bike infrastructure, and environmental impact indicators. The results reveal that most services in the two districts are accessible within a 15-minute walk or bike ride. However, essential facilities (e.g., universities and hospitals) exceed this threshold (20–30 min). The green area per inhabitant (17 m2/capita) meets WHO and European recommendations. The NAC has clean, green public transportation and 94.26 km of cycling lanes. For the sustainability indicator, air pollutants (PM10 and NO2) slightly exceed the WHO guidelines, but SO2 and Ozone levels are below the limits. The estimated waste per capita (274 kg) is lower than Cario and other counties. The findings suggest the NAC has the potential to fulfill the 15-MC concept through mixed-use developments, accessibility, and sustainable planning. This study serves for future research and modeling of the NAC when it is fully occupied.