In Phase I, the purpose and need of the project was defined. The potential effects of the project were determined and measures to minimize adverse effects were proposed. A reasonable range of alternative grade crossings locations were evaluated, and the environmental and cultural impacts of each alternative were analyzed. The results of the analysis were the selection of a Preferred Alternative based on factors such as environmental resource impacts and engineering feasibility. Preliminary Engineering plans were then completed for the Preferred Alternative.
Public participation is an important element of the Phase I process. The Oak Street Bridge Replacement Project followed the IDOT Context Sensitive Solution (CSS) approach to public involvement. This included five Community Working Group (CWG) Meetings and two public meetings.
The majority of funds for the project are coming from the Illinois Commerce Commission (ICC), the Illinois Department of Transportation (IDOT) and the Federal Highway Administration (FHWA). The remaining funds were procured through grants from various organizations. IDOT and FHWA representatives periodically reviewed Phase I to monitor the process and to ensure that the developing design met state / federal guidelines and engineering standards. Phase I was completed when the state and federal authorities approved and signed the Phase I final project development report.