Some experts suggest that urban design plans in US cities may lack adequate coverage of the essential design aspects, particularly three-dimensional design aspects of the physical environment. Digital urban models and information technology tools may help designers visualize and interact with design alternatives, large urban data sets, and 3D information more effectively, thus correcting this problem. However, there is a limited understanding of the impact that these models may have on the quality of the design product and consequently hesitation about the appropriate methods of their usage. These suggest a need for research into how the usage of digital models can affect the extent with which urban design plans cover the essential design aspects. This research discusses the role digital models can play in supporting designers in addressing the essential design aspects. The research objective is to understand how the usage of digital models affects the coverage of the essential design aspects. The research applies a novel perspective of examining both the methods of modeling-supported urban design and the design content of urban design to attempt to reveal a correlation or causal relation. Using the mixed method approach, this research includes three phases. The first, literature review, focused on reviewing secondary sources to construct theoretical propositions about the impact of digital modeling on urban design against which empirical observations were compared. Using qualitative content analysis, the second phase involved examining 14 plans to assess their design content and conducting structured interviews with the designers of four selected plans. The third phase involved sending questionnaire forms to designers in the planning departments and firms that developed the examined plans. The analysis results were compared with the theoretical propositions and discussed to derive conclusions. The extent of design aspects coverage was found to be correlated with the usage of digital modeling. Computational plans appear to have achieved a higher level of design aspects coverage and a better translation of design goals and objectives. In those plans, 3D urban-wide design aspects were addressed more effectively than in conventional plans. The effective usage of the model's functions appears to improve the quality of the decision-making process through increasing designers' visualization and analytical capabilities, and providing a platform for communicating design ideas among and across design teams. The results helped suggest a methodological framework for the best practices of modeling usage to improve the design content.