MUNSTER, Ind. — Transportation officials in Indiana and Illinois expect to complete a revised environmental impact assessment for the proposed Illiana Expressway between the two states this fall.

Environmentalists have fought the 47-mile tollway plan, arguing it would threaten the Midewin National Tallgrass Prairie south of Chicago. Some planners also question the need for the roadway and its financial viability.

Illinois shelved the $1.5 billion project when Gov. Bruce Rauner took office in 2015.

But the (Northwest Indiana) Times reports ( ) the Illinois Department of Transportation is cooperating with the revisions while making it clear it won’t pursue the road without “a determination that the project is financially viable.”

A federal judge last year rejected the earlier environmental review, citing flaws including a failure to thoroughly evaluate the impact on the tallgrass prairie.

Information from: The Times,