Calhoun Road and I-94 Bridges - Brookfield, WI
Much was at stake on the Calhoun Road project as the design team faced nearly any challenge imaginable. Any one challenge could have easily stalled, or even prevented, project completion.
A 1.3-mile stretch of Calhoun Road in the city of Brookfield, Wis. was reconstructed from a two-lane rural to a four-lane urban divided roadway (with six lanes on the northern end).
The project challenges were significant when paired against the City of Brookfield’s requirement of a three year, accelerated schedule. It’s highly unusual for a project of this complexity, and with this many constraints, to be completed in less than four to five years.
Several challenges required frequent communication and extensive coordination.
Innovative Design Saves $900,000
Design of the Calhoun Road profile under I-94 had significant positive impacts on the I-94 construction costs. Each foot the I-94 structures needed to be raised resulted in about $600,000 of additional construction costs due to the extended construction limits. By adjusting the Calhoun Road profile and splitting the storm sewer trunk line into two trunk lines under I-94, the construction limits on I-94 were limited, saving approximately $900,000.
The storm sewer system was designed with additional capacity to resolve an ongoing drainage issue in an adjacent neighborhood. Without adding capacity to the Calhoun Road system, the City would have been forced to cross I-94 with a new storm sewer pipe at another location. Resolving this situation in this manner saved the City hundreds of thousands of dollars.
Unique Methods Utilized to Treat Stormwater
The design team utilized energy dissipation, level flow spreading and natural filtration principles to treat stormwater within a closely confined space, protecting a sensitive wetland and state threatened species habitat.
The stormwater treatment area was surrounded on three of four sides by I 94, Calhoun Road, and Deer Creek.
Close coordination with the Wisconsin Department of Natural Resources produced a unique storm water treatment system that substantially reduced the treatment area needed compared to more traditional methods.
Threatened and Endangered Species Habitat Protected
The roadway design required habitat creation, habitat preservation and habitat connectivity for a state threatened species. Butlers’ Gartersnake habitat was connected on either side of the new road with specially designed “shelves” under the Deer Creek bridges with open steel grates in the concrete median to allow light under the bridges. To enhance driver safety, the grate was designed to be traversable by trucks, avoiding the need for obtrusive beam guard.
Special provisions were included to net bridges to prevent swallow nesting, restrict work during fish spawning periods, and install snake exclusion barriers. Because the construction began after some of the restricted dates, coordination with the City of Brookfield was required to install swallow nets and snake exclusion barriers prior to construction.
Special fencing details discouraged snakes from entering the construction zone. Special rootstock and seed mixes were utilized to restore and enhance endangered species habitat.
Historical Property Impacts Coordinated
The project team coordinated impacts to two historical properties eligible for the National Register of Historical Places. Several outbuildings were removed, one of which was occupied by three businesses that required relocation. The project team developed a Memorandum of Agreement that would satisfy the State Historical Society and the Elmbrook Historical Society concerning the historical preservation of portions of these buildings. Public education exhibits regarding the history of the Jacob Ruby Farmstead were created. Building materials were salvaged and will be put on display by the Elmbrook Historical Society.
Strong Public Opposition Overcome
The public’s initial reaction to the project was highly controversial and included a locally organized opposition group. The design team responded by launching a strong communication effort that used the Internet to communicate with the public not only during the construction phase but the design phase as well. Citizens appreciated being able to use this tool to learn about the project prior to public meetings and construction.
The City of Brookfield has commented that the project has been the source of much praise and compliments from the public and elected officials.
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