Details on IL-75 bridge replacement over the Rock River

An virtual meeting about the IL 75 Over the Rock River Bridge Replacement informed residents of Rockton, Illinois. 43 people logged on to the meeting on Tuesday, Jan, 28, 2025.

A team of engineers from IDOT (Illinois Department of Transportation) gave an overview of the project. During the presentation, they discussed maintenance of traffic during construction and the proposed structure details.

Mike Cima, Director of Bridges and Structures and the project manager from Quigg Engineering, said, “This project involves the complete replacement of the bridge carrying IL 75 over the Rock River in Rockton. The project limits will begin just north of East River Street and end south of Hawick Street.” IL 75 is also known as East Blackhawk Blvd. in downtown Rockton.

Sara Parisien served as the organizer and moderator of the meeting.

When making plans, IDOT considered the bridge's age and history. Stephen Mack built the first bridge across the Rock River in the early 1840s, west of the current bridge, but it washed away in 1851.

The current bridge was built in 1927, so elements of it are nearly 100 years old. It was reconstructed in 1974 with a new superstructure placed on the existing abutments and piers. The bridge was last repaired in 2009. Many of the bridge elements are deteriorating and need to be addressed.

“Something needs to be done to ensure that the bridge in this location can continue to do its job in getting pedestrians and vehicles safely across the river,” Cima said.

The project team looked at several options, including bridge repairs, reconstructing major elements of the bridge or replacing the bridge.

Just replace it all

After completing their analysis, they determined the best long term solution is to replace the bridge.

Phase One of the project, which is happening now, involves preliminary engineering. Phase Two is the detailed design for the bridge. Phase 3 - the construction - is set to begin in 2027.

Traffic maintenance during the construction phase is estimated to start in 2027. At times, the bridge will be closed during construction. Traffic will be detoured to the IL 2 bridges.

Closures will be kept at a minimum, and a notice will be posted as work is being done.

Temporarily closing the road will result in reduced construction time and a 25% reduction in project costs.

Plus a bike path

When complete, the new bridge will be 590 feet long, slightly longer than the existing bridge and will be slightly wider with the addition of the multi-use path on each side.

A proposed bike path on IL 75 over the bridge will connect the proposed East River Street trail to the existing trails in Settlers Park.

Construction of the East River Street bike trail is scheduled to start later this year. The bike facilities on the new bridge will be completed in the 2027 time frame with the new bridge construction.

Part of the project includes the creation of a new bike path with accommodations at East River Street. This is separate from the Old River Road bike path project to Stephen Mack Middle School, which is not active right now. Currently the Village of Rockton has several different projects in the works.

During the virtual meeting, IDOT staff showed a bridge rendering with an elevation view. It will include a pedestrian observation deck with a flagpole, memorial plaques, a sidewalk and a lookout area which will be restored on the new bridge.

When complete, there will be two traffic lanes with five foot sidewalk, and a 10 foot wide multi use path on each side.

“The state plans to purchase an additional right of way and a temporary easement required to allow for construction of the multi-use path and the reconstruction of the bridge,” Cima said.

The project cost is an estimated 12 or 13 million dollars.

Funds are generated from the Illinois gas tax and applied to the road fund. The state adds a portion along with a large portion of Federal funding. Funds have been allocated specifically for this project.

The state will work with local authorities and groups to minimize impacts on Settlers Park during the construction.

Questions and answers

Listeners were allowed to submit questions that were addressed after the presentation, with an extended opportunity to submit questions up to Feb. 11 which will be on the record as part of this meeting.

One listener asked, "Will there be any coordination ongoing between Old Settlers Days and any potential impact from the project?"

In reply, “We are aware that it is a big event that we will have to coordinate.  Engineers said that it lands in mid summer, during construction.”

“We can have verbiage in the contract to make sure that it doesn't affect OSD in the park. Engineers will be working with them on it. There is no guarantee of it being open, but can put verbiage in the contract that OSD will not be affected.”

Asked how much time the detour will add to commutes, engineers said that an extra 10 minutes should be allowed.

Engineers are working with environmental agencies and are planning to do an environmental impact assessment and will be looking into various safety aspects.

The Jan. 28 presentation is available on the project website, https://il75rockriverbridge.com/, which includes all of the details discussed.

The project is expected to last approximately a year, taking into consideration weather conditions or other unexpected occurrences. Construction will be complete 100 years after engineers built the current bridge and 185 years after Stephen Mack built his.