Illinois and Indiana don’t often agree on much, but the governors of both states recently touted the building of the Illiana Expressway. At a cost of a billion dollars, the Illiana would link Chicago’s far southern suburbs to southern Lake County, Indiana with an alternative east-west route for traffic. Supporters say the project would generate thousands of jobs for decades to come.

But in a critical report released Wednesday, the Metropolitan Planning Council of Chicago says the highway won’t create nearly enough jobs or economic development to justify its cost.

“If you take $1 billion and you invest it anywhere, you’re going to create some construction jobs and near-term jobs without a doubt. That billion dollars is going to have an economic ripple,” Peter Skosey, executive vice president of the Metropolitan Planning Council (MPC) of Chicago, told WBEZ on Thursday. “The real question is what is the sustained ripple from that investment? And that’s where we think the Illiana falls short.”

The MPC is an independent, nonprofit and nonpartisan organization that seeks to develop strategies to deal with the Chicago area’s planning and development challenges.

Using data from the highway agencies in Illinois and Indiana, the MPC has concluded that the Illiana will provide few benefits in exchange for “high and uncertain costs.” The MPC is opposed to the Chicago Metropolitan Agency for Planning, a separate government agency, adding the Illiana to its ‘GO TO 2040’ plan. The plan is essentially an infrastructure and road priority list for the Chicago area.

The Chicago Metropolitan Agency for Planning (CMAP) will vote in October whether to include the Illiana on the list.

The MPC is also sending its findings to the Northwest Indiana Regional Planning Commission, which is developing its own 2040 plan and will decide soon whether to fund Indiana’s portion of the Illiana.

Skosey says the Illiana’s estimated project cost of $1.3 billion is too low. He says building the expressway will result in almost no improvement in congestion on existing highways and produce 1,000 fewer long-term jobs.

“It would effectively redistribute jobs and population from the center of the region,” Skosey said.

Over the past year, public hearings have been held on both sides of the state lines with residents who will likely be affected by the Illiana. Some residents expect to lose their homes if the highway is built.

Proponents say the Illiana is needed to foster development in the region and could also serve a proposed major airport near Peotone.

But the Illiana faces a tough road ahead.

In July, three environmental groups, including the Sierra Club, filed a federal lawsuit challenging the impact to nature areas in Illinois.

CMAP is also questioning IDOT’s own cost estimates for the Illiana.

“Given the available information, CMAP’s observation is that IDOT’s estimate of the project cost is low relative to other comparable projects,” CMAP wrote in a June 2010 letter to the Illinois Department of Transportation. “A more detailed cost estimate would be required to perform a robust evaluation of the proposed project’s financial viability and its impact on GO TO 2040’s fiscal constraint.”

In August of this year, Ann Schneider, secretary of IDOT, wrote a letter to CMAP in defense of the Illiana Expressway and its impact on Will County.

“Will County has emerged as a nationally significant inland port, with billions of dollars in goods being imported and exported. Beyond our comprehensive analysis, it’s simply common sense that we make strategic transportation investments such as the Illiana Corridor project to maintain and strengthen this existing economic center, and in doing so, strengthen the region,” Schneider wrote.

Follow WBEZ NWI bureau reporter Michael Puente on Twitter @MikePuenteNews.