Phase I and Phase II engineering were commissioned by the Grundy County Highway Department to plan and design the widening and reconstruction of Ridge Road (County Highway V37) in Minooka, Illinois. The project included widening an existing two-lane rural cross section to a five-lane urban cross section with a ten-foot-wide multi-use path on the west side of the roadway and a five-footwide sidewalk on the east side of the roadway. To accommodate the widened Ridge Road, the existing CN viaduct was lengthened by converting the existing east abutment into a center pier and adding a new bridge span over the new northbound lanes.
During the planning stage, Wight evaluated the social, economic, environmental, and sustainable design impacts of the potential build alternative, as well as the no-build alternative. Consideration was also given to multi-modal impacts of the proposed design, providing greatly increased pedestrian accommodations throughout the corridor. In general, the build alternative either improved or had a neutral impact on social, environmental justice, and economic considerations. The public outreach component of the study focused on reaching as many people from as many different groups as possible. Traditional advertising, as well as the Village of Minooka’s website and resident call system were utilized to maximize the number of attendees at the public meetings.
Mobile lidar was utilized to collect the existing conditions survey of the project, providing billions of distinct data points, which we filtered to create an existing conditions model much more detailed than what has traditionally been used in the Phase II process. Virtually building from this existing conditions model, we performed our design in full 3D using a new roadway design software, Bentley’s OpenRoads Designer. During Phase II, this approach allowed us to perform detailed design, including accurately determining retaining wall heights and pavement grading at closer intervals than traditionally would be used. This detailed 3D model of the proposed improvement was used to prepare the contract plans.
The northbound and southbound lanes followed separate alignments and PGL’s around the center pier of the CN bridge. The paving details in the areas where the two diverged and converged were quite complicated. In addition, the transition of the pavements from the typical sections to match the CSX grade crossing required precision in order to avoid creating “bird baths” in the final pavement. Wight provided the Contractor and Phase III Engineer with 3D surfaces that defined the intended grades in detail and were incorporated into the Contractor’s model that was used to layout and construct the project.
Constructing a full 3D model in design, starting with detailed existing conditions data and carrying that model through construction, is an innovative approach to transportation project delivery. This approach has proven benefits for large reconstruction projects such as Ridge Road and should be used on future improvements. Ridge Road is the first project we are aware of in Illinois that followed this delivery approach.
