Environmental groups are suing to try to stop a proposed $1.3 billion tollway linking northern Illinois and northwestern Indiana.
The Environmental Law & Policy Center announced Thursday that it filed the suit in Cook County circuit court on behalf of the Sierra Club and Openlands.
They contend that the Illinois Department of Transportation doesn't have authority to continue developing the proposed 47-mile Illiana Tollway.
The lawsuit names the Illinois Department of Transportation and a metropolitan Chicago planning agency that approved the proposed project, even though its board had rejected it. Environmentalists claim board approval is necessary, so the project is illegal.
Illinois Gov. Pat Quinn and Indiana Gov. Mike Pence say the roadway would promote economic development. Critics claim it is unneeded, and would destroy important farmland and wildlife habitat.