Once a project is funded, the S.C. Department of Transportation's Project Development and Environmental Analysis Branch (PDEA) evaluates proposed projects in accordance with established engineering practices and federal and state regulations.

This process involves specialized environmental studies and coordination with regulatory agencies to ensure that both local communities and environmental resources are properly considered. Specialists in fields such as noise and air quality, archaeology, architectural history, biology, land-use planning, and sociology all contribute to assessing the potential impacts of proposed road projects.

Design and traffic engineering studies are also conducted to analyze various roadway options, ensuring that future travel demands are met safely, efficiently, and economically.

Public engagement is a critical component of the process. SCDOT communicates information about proposed projects and seeks feedback through mailings, news releases, public meetings, and other outreach methods. Comments received from the public and partner agencies are then reviewed and addressed, ultimately helping SCDOT determine how and where these projects should be built.