It's not the catchiest name, but Alternative A-71C could mean faster commutes and less gridlock angst for the thousands of Chicago area residents who hate driving through the Circle Interchange.
Illinois Department of Transportation planners have picked a design expected to fix the chronic congestion that plagues the interchange connecting the Dan Ryan, Eisenhower and Kennedy expressways.
Engineers evaluated several alternatives and picked A-71C because it will take a shorter time to construct and offers better ramp alignments, sightlines for drivers and flatter grades, officials said.
"We hope to create something that relieves the stress of driving through the interchange," project management consultant Paul Schneider said.
"There's a lot of weaving areas on the interchange right now; motorists have to make quick decisions and if there's trucks around, it can be treacherous."
The preliminary estimate for the work is $420 million but engineers are still fine-tuning details.
And while the engineering is challenging, so is paying for the project. Funding has dwindled from the state's 2009 capital bill and there's no current legislation in the works. IDOT officials have said they hope to obtain federal grants for the work or there is the possibility of instituting tolls on the improved structure.
Design features include:
• A two-lane flyover ramp from the northbound Dan Ryan to the westbound Eisenhower. The ramp would start near Taylor Street and elevate over Halsted Street, dropping to connect with the Eisenhower.
• Additional through lanes to relieve an existing bottleneck. Currently, there are five lanes to the north and south but only three through lanes in the Circle Interchange section. This would allow for four lanes.
• A bypass ramp north of the Circle Interchange would involve a flyover at Harrison Street linking southbound Kennedy drivers with the University of Illinois at Chicago neighborhood. This would eliminate smaller slip ramps where drivers are weaving in and out of traffic.
• A bypass ramp for drivers headed north on the Dan Ryan destined for downtown Chicago. Located just south of the Circle Interchange, it would allow vehicles to exit onto city streets with less interference with through traffic.
"It will take a lot of merging traffic and diverging traffic out of the circle," Schneider said. "There's so many exits there now, you have to be on your toes."
The 1950s-era interchange handles about 300,000 vehicles a day and was named one of the worst chokepoints in the nation.