The vision of the Illiana Corridor dates back to the 1909 Plan of Chicago by Daniel Burnham and Edward Bennett that included an "Outer Encircling Highway" serving northeastern Illinois and northwest Indiana.

Conceptual highway corridors linking Illinois and Indiana south of Interstate 80 were also studied by regional planning agencies in both states in the 1960s and 1970s.

Following completion of these studies, a memorandum of understanding was signed on June 9, 2010 by the Governors of Illinois and Indiana, which formalized the partnership between the two states for planning a potential new transportation linkage.

The two states' transportation departments were charged with examining potential routes and proposing one through the formal federal interstate-highway planning process.

In late 2012, the bi-state planning group released a draft Tier 1 environmental impact statement which was made final in January 2013.

[12] Sources told the Tribune that Chicago Mayor Rahm Emanuel had decided to oppose the expressway project, which was expected to mean that the city's representatives on the CMAP board would vote against including it in the regional plan.

[14][15][16] CMAP's MPO Policy Committee, which under federal law held the final say on inclusion in the regional plan, met to act on the proposed project.

[17][18] In the end the committee, chaired by IDOT Secretary Ann Schneider, who is an appointee of Governor Quinn, voted 11-8 for inclusion of the Illiana Expressway in the regional plan.

[19] Two of northeastern Illinois' transit agencies, PACE and Metra, received criticism for their representatives' Illiana votes on the MPO Policy Committee.

[36] Cook County Board President Toni Preckwinkle wrote to Illinois Governor Patrick Quinn opposing the project.

"[38] In December, Indiana GOP state representative Rick Niemeyer published an op-ed article explaining his opposition to the project.

[41] In April 2014, the Environmental Law and Policy Center filed a lawsuit alleging that CMAP violated its founding legislation in the process of approving the Illiana.

[42] In October 2014, the Illinois Public Interest Research Group issued a report that criticized the project as unnecessary based on transportation trends and irresponsible financially.

Senators Dan Coats (R-IN) and Mark Kirk (R-IL) and U.S. Representative Pete Visclosky (D-IN) expressed their support for the project.