  Urban design significantly impacts sustainability, particularly in the
context of public transit efficiency and carbon emissions reduction. This study
explores two neighborhoods with distinct urban designs: South End, Charlotte,
NC, featuring a dynamic mixed-use urban design pattern, and Avondale,
Chattanooga, TN, with a residential suburban grid layout. Using the TRANSIT-GYM
tool, we assess the impact of increased bus utilization in these different
urban settings on traffic and CO2 emissions. Our results highlight the critical
role of urban design and planning in transit system efficiency. In South End,
the mixed-use design led to more substantial emission reductions, indicating
that urban layout can significantly influence public transit outcomes. Tailored
strategies that consider the unique urban design elements are essential for
climate resilience. Notably, doubling bus utilization decreased daily emissions
by 10.18% in South End and 8.13% in Avondale, with a corresponding reduction in
overall traffic. A target of 50% bus utilization saw emissions drop by 21.45%
in South End and 14.50% in Avondale. At an idealistic goal of 70% bus
utilization, South End and Avondale witnessed emission reductions of 37.22% and
27.80%, respectively. These insights are crucial for urban designers and
policymakers in developing sustainable urban landscapes.
