Jane Byrne Interchange

The Circle Interchange is an expressway interchange near downtown Chicago, Illinois. It is the junction between the Dan Ryan, Kennedy and Eisenhower expressways, and Congress Parkway. In a dedication ceremony held on August 29, 2014, this interchange was renamed in honor of former Chicago Mayor Jane M. Byrne .This interchange is notorious for its traffic jams. In 2004, it was rated as the country's third-worst traffic bottleneck, with the drivers of the approximately 300,000 vehicles a day using it losing a combined 25 million hours each year. In a 2010 study of freight congestion, the Department of Transportation ranked this section of the I-290 as having the worst congestion in the United States; the average truck speed just 29.41mi/h.DesignThis interchange is logically a turbine interchange, with each of the four mainlines having a single entrance and exit serving both directions of the crossing highway. It does not use the quadruple-decker architecture commonly associated with stack interchanges. Instead, it has a flattened layout, using the long, curving ramps to circumnavigate the crossing of the mainlines. This results in fewer tall bridges and gives the interchange its distinctive "circle" appearance.Both I-90/I-94 and I-290/Congress Parkway have three lanes in each direction at this interchange. Each of the ramps leading to and from the freeways is one lane wide, except for the ramp from eastbound I-290 to eastbound (southbound) I-90/94; this ramp is two lanes wide.