The federal government has signed off on an agreement allowing the existing Elgin-O'Hare Expressway to be converted into a tollway, officials said today.



The U.S. Transportation Department approved an agreement allowing the Illinois Tollway to include the existing highway in its $3.6 billion Elgin-O'Hare Western Access Project, according to officials in Washington, D.C., and Illinois.



Despite the tollway's plans to build a $30 million ramp to access O'Hare property, there is no agreement between the city of Chicago and the major airlines at O'Hare, led by United and American, to construct a western terminal.



And neither will the existing expressway be extended to Elgin, but motorists will pay tolls.



The department's authorization was the last step in the federal review and approval process, according to the tollway.



The Federal Highway Administration and Federal Aviation Administration approved the project's environmental impact review on Dec. 12.



The Elgin-O'Hare Western Access Project will include construction of a new, all-electronic toll road around the western border of O'Hare International Airport.



The new tollway will link the Jane Addams Memorial Tollway (I-90) and the Tri-State Tollway (I-294). The existing Elgin-O'Hare Expressway will be turned into a tollway and will be widened and extended east along Thorndale Avenue to O'Hare.



The project is expected to take 12 years to complete.



The tollway this year is planning to spend $95.6 million to begin work. Potential construction includes noise walls along the existing Elgin-O'Hare Expressway, Rohlwing Road (Illinois Route 53) grade separation and the southbound Elmhurst Road over I-90 bridge.



The actual location and schedule of construction will depend on land acquisition, permits, agreements and utility relocations, the tollway said.



rwronski@tribune.com

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