Phase I Engineering for IL 47 (US 30), Kennedy Road to Cross Street

Lochner performed Phase I services to improve approximately 6.5 miles of IL 47 (US 30) from Kennedy Road north of Yorkville to Cross Street in Sugar Grove. In its existing condition, IL 47 was a two-lane arterial in a primarily rural area, except while running through the Village of Sugar Grove and the City of Yorkville. Phase I engineering services included the preparation of a combined design report; an environmental assessment (EA); a location drainage study; three bridge condition reports and hydraulic studies; six type, size, and location plans; and nine intersection design studies in accordance with policies and criteria from the Federal Highway Administration (FHWA) and Illinois Department of Transportation (IDOT).

As a context sensitive solutions project, input was solicited from a citizens advisory group, project study group, local officials, and other stakeholders through a tailored, coordinated public involvement process to determine a preferred alternative. The preferred alternative replaced the existing two-lane road with a four-lane cross section consisting of two 12-foot lanes in each direction, a 30-foot-wide landscaped center barrier median, and a 10-foot shared-use path. The drainage system was closed as needed in urban areas and utilized open ditches in rural areas.

Additionally, Lochner performed a crash analysis to help inform the Phase I roadway design, which improved capacity, modernized geometrics, and provided reasonable access. The design included new vertical and horizontal alignments that flattened curves, improved sight distance, removed superelevations, and improved levels of service.

The drainage study and hydraulic reports included analyses of ditches, closed drainage systems at railroad underpasses, the Blackberry Creek crossing, and the Rob Roy Creek, which runs tangent and adjacent to the roadway for over 1.2 miles and crosses on a diagonal. The analyses considered significant impacts to floodways and floodplains and required compensatory storage for permitting. As the project overlapped multiple boundaries, permit coordination included two IDOT districts, two U.S. Army Corps of Engineers regions, two Illinois Department of Natural Resources regions, two counties, and several other agencies.

Type, size, and location plans and bridge condition reports were included for four water crossings and two locations where the roadway crossed under rail structures. Both rail bridges carry two BNSF tracks. The project anticipated that the bridges would be replaced to accommodate the widened roadway and the southern rail bridge would be widened to accommodate a future third track. Staging of the bridge crossings minimized impacts to rail and roadway traffic, and a permanent structure was designed to accommodate both temporary rail traffic and the future third track. Proposed box culverts were anticipated to replace existing structures as practical for cost and maintenance considerations.

Lochner coordinated design with BNSF Railway, including loading and shoo-fly alignments. Track alignments met BNSF requirements by maintaining existing track speeds for passenger trains and freight trains at the two locations—a double-track mainline on tangent and mainline with passing siding on a curve.

All improvements were reviewed in the context of impacts including wetlands, floodplain, right of way, and structures. Designs were targeted to accommodate construction of the roadway and structures with minimal interruption to roadway and railroad traffic.