The Illinois Tollway is turning to advanced construction techniques to help keep traffic flowing and trains moving while a new Burlington Northern Santa Fe (BNSF) Railway Bridge is built over the Central Tri-State Tollway (I-294).
A key to the construction of the temporary, bypass bridge will be assembling segments of the span next to I-294 and then using a self-propelled modular transporter (SPMT) to lift and maneuver the completed portions of the bridge into place over the roadway.
Using those techniques will significantly reduce the impact on Tollway customers by requiring few lane closures on I-294 while the bypass or “shoefly” bridge is being installed above it.
“We’re always looking to work with our contractors to encourage innovation, reduce construction time and deliver projects more efficiently,” said Illinois Tollway Executive Director José Alvarez. “In this case, our team is excited to see this new approach on this unique and challenging project.
The Tollway is constructing a shoefly bridge that will allow commuter and freight trains to continue operating without interruption while the BNSF Railway Bridge is being removed and replaced. The Tollway is removing the existing three-track BNSF Bridge and replacing it with a longer, wider, two-span steel beam structure that will accommodate four tracks and allow the Tollway underneath to be widened and improved.
To build the shoefly bridge, construction crews working in roadside staging areas will assemble bridge segments from steel beams while they are safely away from traffic. Using roadside staging areas also allows them to work during the day without interruptions and near ground level in a safer environment.
Once all six segments required for the shoefly bridge are assembled, crews will use an SPMT vehicle – a combination of multi-axle platforms operated through a computer-controlled system – to lift, carry, and set the very large and heavy segments of bridge beams into place. The motorized vehicle moves at walking speed and is capable of carrying the large structures and positioning them precisely into final position.
Using the SPMT technology will allow the Tollway to reduce the major impact of construction on its customers by installing all six segments over two weekends, compared to the two months of overnight and weekend lane closures with full stops that typically would be required if the bridge were constructed using conventional building techniques.
Delivery of materials to the jobsite located just south of the BNSF Bridge is scheduled to begin in May and workers will start the process of assembling approximately 24 steel girders into six bridge segments. This work is anticipated to continue through June.
After assembly is complete, the Tollway will schedule two weekends of extended closures this summer on the Central Tri-State Tollway (I-294) for bridge segment installation with the SPMT vehicle on one side of the Tollway at a time. One weekend of closures will allow the Tollway to reduce I-294 northbound traffic into a single a counterflow lane on the southbound side. The second weekend of closures will allow the Tollway to reduce I-294 southbound traffic into a single a counterflow lane on the northbound side.
The Illinois Tollway is reconstructing the BNSF Railway Bridge, which carries the triple-track railroad over I-294 between Hinsdale and Western Springs, to accommodate the reconstruction and widening of the Central Tri-State Tollway. The existing bridge will be replaced with a longer, wider two-span steel beam structure that will accommodate four tracks and will allow for reconstruction and widening of the Tollway underneath. The new fourth track on the bridge will be used for maintenance purposes by BNSF.
The BNSF Railway Bridge Project is being coordinated with Metra, Burlington Northern Santa Fe (BNSF) Railway and Cook County, along with local municipalities, park districts, as well as police and fire departments.
The work is part of the Illinois Tollway’s 15-year, $14 billion capital program, Move Illinois: The Illinois Tollway Driving the Future. Construction information about the BNSF Bridge Project is available in the Projects section on the Tollway’s website here.