STV’s Chicago team recently led members of industry organizations on a tour of the Harrison Street Viaduct reconstruction site.
Located directly west of the south branch of the Chicago River, and a mere 15-minute walk from STV’s downtown Chicago office, the Harrison Street Viaduct serves as a vital east-west thoroughfare. The corridor connects commuters traveling in and out of the city’s downtown Loop, accommodating freight trucks, vehicles, pedestrians and cyclists in both directions. With Union Station only three blocks away, the 780-foot-long viaduct provides critical access across the Chicago River and connects various transit modes near one of the city’s busiest rail hubs.
The project site is bordered by key landmarks: on the north, the Old Chicago Main Post Office—a now-modernized office complex with major corporate tenants like Walgreens; and on the south, the United States Postal Service’s (USPS) central distribution facility. The viaduct itself intersects with major rail lines, with 18 Amtrak and Metra tracks running directly below.
Within the context of this site, STV is providing construction management (CM) services on behalf of the Chicago Department of Transportation (CDOT) for the $21 million staged removal and replacement of the viaduct. The existing vehicular bridge structure is being replaced with a reinforced concrete deck, wide-flange steel beams and piers supported on the current foundation to restore functionality, bring the viaduct up to current standards and extend its useful life. The scope also covers two new ADA-compliant sidewalks, protected bike lanes in both directions, roadway resurfacing and reconstruction with a latex overlay and related roadway work.
Construction is being carefully phased to maintain accessibility, and STV has implemented maintenance of traffic (MOT) measures to minimize disruptions and maximize the accessibility of surrounding businesses, with three detours established to accommodate vehicles, bicycles and pedestrians, respectively. The project team has also worked tirelessly to mitigate the impact on local stakeholders, including Amtrak, Metra and Union Station to ensure rail operations remain uninterrupted, as well as USPS, other property owners and community groups.
In early October, Aziz Mirza, PE, assistant resident engineer, hosted a tour for members of the Illinois Asian-American Civil Engineers (IAACE) and the American Society of Civil Engineers Construction Institute (ASCE-CI), offering insights into the project’s complexities. The event followed a similar tour conducted in Spring 2023 for the Construction Management Association of America’s (CMAA) University of Illinois Chicago (UIC) student chapter, led by Mirza and Kevin Gartley, PE, resident engineer.
During the tour, Mirza led participants from the east to the west end of the site, highlighting different stages of the project’s progression, including the use of specialized construction equipment like paving machines and the application of materials like the latex road surface. Following the site walk, his presentation at the field office offered further context, featuring photos that illustrated the full transformation—from demolition to the construction of new piers, framing, steel beams and, finally, the concrete bridge deck.
“What I enjoy most about this project is the focus on improving access. Construction can be inconvenient, but the end result is worth it,” Mirza said. “And with UIC just a few blocks away, where I studied, it’s particularly meaningful to improve access to and from the campus, supporting the students and the community around the school.”
With the viaduct crossing 18 active rail tracks leading into Union Station, the project has faced unique constraints, often requiring work to be conducted overnight from 11 p.m. to 5 a.m. or on weekends to avoid disrupting train services. The need to maintain continual access to the USPS property on the south side and coordinate with the Old Post Office and its occupants have added additional layers of complexity.
“The tight site and close proximity to so many stakeholders have made this project really challenging,” said Badi Alsalami, senior inspector, who accompanied the tour. “Coordinating with train operations—working closely with Amtrak and Metra to avoid disrupting their schedules—while balancing access needs for the many local businesses and commuters who rely on this area has required a lot of careful planning, as well as flexibility when adjustments are needed to keep construction moving safely.”
To manage these complexities, STV’s team has been tasked with preparing detailed construction progress updates, coordinating access and laydown areas, developing relocation schedules and communicating any potential impacts with stakeholders, including the local alderman’s office.
The reconstruction of the Harrison Street Viaduct, now two years in the making, is scheduled for completion in Spring 2025. Once finished, the project will not only enhance the structural integrity and safety of this vital commuter corridor but also improve overall access and mobility for all who traverse this part of downtown Chicago.
