The article presents a new way to measure the physical structure of U.S. cities, going beyond just density and gradients. By looking at multiple dimensions, researchers can better understand how cities grow and develop. They created different variables and indices to describe urban areas at different levels. By grouping cities based on their form and land use, planners and policymakers can make better decisions about transportation and land use. This method helps identify patterns in urban areas that can lead to more efficient planning in the future.