ROCKTON, Ill. — A major infrastructure upgrade is underway along Illinois Route 2, where the Illinois Department of Transportation is overseeing a first-of-its-kind bridge replacement strategy designed to save both time and taxpayer dollars.
The project — located over the Rock River between Rockford, Rockton, South Beloit and Beloit, Wisconsin — involves replacing two 60-year-old bridges that have exceeded their intended lifespan and carried strict weight limits for vehicles.
Instead of building a temporary crossing in the river, IDOT approved a unique solution: sliding the existing southbound bridge more than 40 feet toward the northbound bridge to form a high-level tramway above the water. This platform allows crews to demolish and rebuild each structure without disturbing the river below.
“This approach is being monitored for its potential time and cost savings,” IDOT officials said, noting it is part of the agency's busiest infrastructure investment period in state history.
Matt Hardt, District 2 construction engineer, said the innovative strategy avoids major flood risk and environmental disturbance often caused by building temporary causeways.
“The process to rebuild the Illinois 2 bridges poses less intrusion in the river as the tramway is high above it,” Hardt said.
“These temporary tramways and causeways would have been susceptible to river level fluctuations with potential for lost time if they were overtopped by flooding.”
The project began in early 2024. Temporary supports were installed between the bridges, followed by hydraulic machine skates and slide rail columns that allowed crews to shift the 3-million-lb., 588-ft-long structure 8 to 10 inches every 30 seconds. The entire move took just 12 hours — a milestone never seen before in Illinois.
“It’s innovative and something they have never tried before,” said engineering leader Mahmoud Etemadi.
“There have been structures smaller than this that were done, but this was a big, big thing.”
Helm Civil of Freeport was awarded the construction contract with a $25.3 million bid. The project also supports safer mobility on a corridor that carries 8,550 vehicles per day and connects several regional communities and cross-state travelers.
Once fully complete, the new bridges will improve weight capacity, reduce maintenance needs and support the modern transportation demands of the Rock River communities for decades to come.
The success of the sliding method may influence future IDOT bridge replacements statewide — especially where waterway protection and cost efficiency are priorities.
Originally reported by Construction Equipment Guide.
