Process
The intersection of Shawnee and Fort Amanda Roads had a level of service D. This meant long traffic delays and waiting at the intersection for several cycles of the traffic light. Within 100 feet of the intersection was a bridge over the Ottawa River; replaced as it was deemed structurally deficient. DLZ studied improvement options to determine the appropriate number of lanes required for the bridge to improve the intersection’s capacity. The bridge currently limits southbound movements. DLZ prepared a red flag summary, an existing and future conditions report, and a conceptual alternatives analysis. Finally, DLZ delivered a strategic plan to move the project forward.
DLZ Alternatives Following the ODOT PDP process
DLZ studied several alternatives, including a no-build option; improvements to the existing three-lane cross-section; widening Shawnee Road to four lanes by adding northbound and southbound right-turn-only lanes, along with widening Fort Amanda Road at the intersection; widening Shawnee Road to five lanes with widening improvements on Fort Amanda Road; and installing a two-lane roundabout at the intersection. For each alternative, DLZ evaluated access management considerations, including service roads to alleviate turning movements, fewer full-access driveways, and safety improvements. As part of the Conceptual Alternatives Analysis (CAS), DLZ presented an evaluation of each conceptual alternative at a public informational meeting to gather input. At the end of Step 4 of the ODOT Major PDP, the project transitioned to the ODOT Minor PDP because DLZ was able to limit off-corridor improvements, as summarized in the CAS Strategic Plan.
Second Phase of the Shawnee Corridor Study
In the second phase of the corridor study, DLZ performed the feasible alternative analysis, reducing the alternatives for the Preliminary Engineering Study (PES) from eight to two alternatives (five-lane section with a traffic signal, roundabout). After the initial geometric layouts, DLZ met with the Allen County Engineer and major stakeholders and added a second roundabout alternative to ensure a complete evaluation. With the concurrence of ODOT and the County, DLZ also performed Phases I and II ESA studies. To obtain a more complete alternative analysis in reaching the preferred alternative, DLZ worked with an appraiser for an in-depth analysis of right-of-way costs.
The second Public Involvement meeting consisted of a brief presentation of the study process, a short educational presentation on modern roundabouts, and a review of the Feasible Alternatives Matrix Analysis and the Recommended Alternative, which was Alternative #3–Roundabout (NE). Public comments were collected and the majority of them were positive about the roundabout alternative. Therefore, the summary for Concurrence Point #2 showed Alternate #3 to be the Preferred Alternative.
Subsequently, DLZ prepared plans and specifications for the construction of the roundabout option, along with bridge replacement plans. Design elements in the plan set included: road geometrics, drainage, maintenance-of-traffic, lighting, landscaping, signing, pavement markings, bridge, utility relocations, and signal removals. DLZ also obtained permits and performed surveys and right-of-way services.
