2010 Top 10 Roads - No. 3

Running down the western boundary of Chicago’s downtown “Loop,” Wacker Drive parallels the Chicago River and forms one of the Windy City’s landmark structures, but it is suffering from aging structures and outdated design.

One of the landmark’s most prominent features, its lower level, where in the old days boats on the Chicago River delivered goods to the downtown businesses, has become a liability.

At the southern end of Wacker Drive is an interchange with Congress Parkway, whose extension, the I-290 Eisenhower Expressway, is a major artery into downtown from the western suburbs. Commuters, tourists and commercial trucks use I-290 to reach the city’s businesses and cultural attractions. Wacker Drive carries traffic from the interchange to the rest of the downtown area, including the North Michigan Avenue business district north of the Loop and Lake Shore Drive on the eastern edge of the Loop.

The trouble is that the Congress Parkway interchange is a mass of outdated geometry, inadequate lighting and degrading structures. The interchange consists of a 19-span double-deck, reinforced concrete frame structure, three reinforced-concrete box tunnel structures, a reinforced-concrete retained-earth structure and several reinforced-concrete retaining walls. Among the improvements to the interchange are new lighting for the tunnels and roadways, -including transitional lighting from one to the other; moving the point where the eastbound Congress Parkway exit ramp splits to join Wacker Drive or Franklin Street to give drivers more time to prepare for the split; widening of Congress Parkway to allow for acceleration and deceleration lanes; and adding an acceleration lane for vehicles entering Congress Parkway from Wacker Drive.

By covering the roadway tunnels as much as possible, the Chicago Department of Transportation plans to turn the area into a park and a scenic gateway into the city.

At press time, crews had been able to get back on schedule after a strike halted all work from June 29 until July 21.

“The private utility companies are continuing with their work in the viaduct section of Wacker Drive,” Douglas Jakalski, P.E., vice president and chief civil engineer at T.Y. Lin International, the project’s designer, told Roads & Bridges. “In this case, because it’s so congested on lower Wacker Drive with utilities and foundation elements and everything else, it’s extremely tight working conditions. Getting the utilities relocated down there in advance of doing all the foundation work is critical."

Utilities include private and public gas, water and electrical main service lines.

Work also is under way on foundation elements for the widening of the Congress Parkway Bridge and for the new pump station in the Congress Parkway Interchange. The pump station is needed to remove any water that seeps into the interchange tunnels, which are below the level of the nearby Chicago River.