Supporters of the Illiana Expressway have defeated an attempt to scrap the project during a meeting of a regional planning organization.
The planned 47-mile tollway between Illinois and Indiana is one of Illinois Gov. Pat Quinn's top public works priorities. Opponents call it a boondoggle.
The Metropolitan Planning Organization Policy Committee met Thursday in Chicago to consider draft updates to the region's long-term infrastructure and land use plan.
A motion to approve the update without the Illiana failed in an 10-8 vote.
Quinn and his department of transportation argue the project will be a massive job generator and a relief valve for Interstate 80 and other congested roadways.
Critics say the $1.5 billion project is unnecessary and warn it will leave taxpayers on the hook if toll revenues fall short.