IL 336 – Northeast Quadrant of the Macomb Bypass

Summary

Kaskaskia Engineering Group, LLC (KEG) acted as a subconsultant for the roadway design of the northeast portion of a four-lane, divided highway bypassing the City of Macomb in McDonough County, Illinois. The northeast bypass is a bypass route for US 67 around the east side of Macomb and is designated as US 67 (FAP 310). The proposed bypass has the classification of a principal arterial highway. There was no existing roadway alignment at this location.

Project

Roadway design services included providing conceptual maintenance of traffic plan, guardrail design, erosion and sediment control plan, two hydraulic reports, removal plan, pavement marking, and signing plan for 5.8 miles of a new four-lane expressway on new alignment from just south of Illinois 136 to just west of US 67. For the 0.6-mile southern end of the project, KEG was responsible for the vertical and horizontal design and the drainage design.

The conceptual maintenance of the traffic plan provided suggested alternate routes and construction signing to detour traffic around the construction of the bypass. Erosion and sediment control plans were designed to accommodate both the existing and proposed drainage patterns necessary to accommodate the roadway ditching and proposed culverts. Since the highway was a new roadway on a new alignment, a detailed plan for proposed pavement marking and highway signing was required to integrate the new roadway into the existing highway system.

KEG prepared two hydraulic reports for this project. KEG was responsible for the HEC-RAS models for the natural, existing, and proposed conditions for each of the sites. One of the crossings, over an unnamed tributary, is serving as a wildlife crossing. KEG worked with the structural engineer to develop options for the configuration to maximize the wildlife access based on the water surface elevation for the different storm events. The other crossing is a proposed triple box culvert crossing Kepple Creek, a tributary to the East Fork of the LaMoine River. This analysis also included two structures under an existing roadway, University Drive, that were in close proximity upstream and downstream of the proposed crossing. KEG worked closely with the design engineers and the district to develop options to reduce existing flooding on University Drive and minimize impacts due to the new crossing by reconstructing the upstream crossroad culvert for University Drive.