  Enhanced efforts in the transportation sector should be implemented to
mitigate the adverse effects of CO2 emissions resulting from zoning-based
planning paradigms. The innovative concept of the 15-minute city, with a focus
on proximity-based planning, holds promise in minimizing unnecessary travel and
advancing the progress toward achieving carbon neutrality. However, an
important research question that remains insufficiently explored is: to what
extent is a 15-minute city concept within reach for US cities? This paper
establishes a comprehensive framework to evaluate the 15-minute city concept
using SafeGraph Point of Interest (POI) check-in data in the 12 most populous
US cities. The results reveal that residents are more likely to rely on cars
due to the fact that most of their essential activities are located beyond
convenient walking, cycling, and public transit distances. However, there is
significant potential for the implementation of the 15-minute city concept, as
most residents' current activities can be accommodated within a 15-minute
radius by the aforementioned low-emission modes of transportation. Our findings
can offer policymakers insight into how far US cities are away from the
15-minute city and the potential CO2 emission reduction they can expect if the
concept is successfully implemented.
