Elgin O’Hare Western Access From Devon Avenue to Pratt Boulevard

RS&H is serving as a design engineer for part of the Elgin O’Hare Western Access Tollway, I-490 from Devon Avenue to Pratt Boulevard, and was designated a project of national and regional significance by federal transportation legislation. The new 7-mile corridor connects two of the busiest roads in Illinois, I-294 and I-90, and will improve travel efficiency, reduce congestion, and support an estimated 120,000 vehicles per day. This project is anticipated to enhance the economic development of the area, creating an estimated 65,000 jobs. RS&H partnered with the Illinois Tollway to address and overcome these challenges. The project is directly adjacent to O’Hare International Airport, one of the busiest airports for passenger traffic, flight operations, and one of the largest air cargo gateways in the world, spanning numerous rail lines including the O’Hare West Yard and Bensenville Rail Yard, which handle millions of freight cargo containers every year.

The main bridge structure carrying I-490 over the Union Pacific Railroad has complex bridge geometry due to site constraints. The design of this bridge immediately became the focus for identifying efficiencies and eliminating constructability concerns. RS&H reviewed the initial concept design and determined another interchange configuration should be considered to improve design efficiency, driver expectancy, overall constructability, and reduce bridge spans. RS&H evaluated multiple bridge types/configurations to produce a design that considered the construction and lifecycle cost, operations, geometric constraints, tolling impacts, safety, and adjacent property impacts. RS&H’s analysis of a new interchange configuration and bridge reconfigurations reduced the size of the I-490 bridge by over 30 percent and saved more than $20 million in costs for the Tollway. RS&H’s visualizations of each design alternative conveyed the aesthetics and functionality of each option which convinced the Tollway, their local agency partners, and the public of the new alternative design.

The proposed design and bridge erection methods were analyzed for impacts to airspace requirements utilizing 3D models. RS&H’s thorough understanding and evaluation of hazards to navigable airspace allowed the Illinois Tollway to coordinate with jurisdictional agencies without delay.

Additionally, RS&H has partnered with the Illinois Tollway to deliver this project as a Pilot for their new 3D Models as a Contract Document program, replacing portions of the plan documents like cross sections with 3D surface files for the contractor’s use. The RS&H team has provided guidance in the development of the Illinois Tollway’s program and continues to support and advocate for its continued development.