PORTAGE, Ind. (AP) - Federal approval for the Illiana Expressway toll road has been delayed by concerns from the U.S. Fish and Wildlife Service partly over how the project might impact endangered species, an Indiana Department of Transportation project manager said.

James Earl told members of the Northwestern Indiana Regional Planning Commission on Tuesday that federal officials have raised concerns about how the highway would affect endangered sheepnose mussel and the threatened long-eared bat, as well as its impact on the Midewin National Tallgrass Prairie in Illinois.

Environmental groups have been talking about concerns about the highway since the first draft environmental impact study was in 2012, Andrew Armstrong, a staff attorney with the Environmental Law & Policy Center that has filed two lawsuits trying to stop the highway, told The Times of Munster (http://bit.ly/1nwVWTi ).

“That we are now this far along in the process and we still don’t have an opinion on endangered species, that just makes it obvious that this project has not received the thorough consideration it needs,” Armstrong said.

Earl says the federal record of decision that originally was expected by the end of May is now expected by September.

The four-lane highway would run between Interstate 65 near Lowell in northwest Indiana and I-55 near Wilmington, Illinois, 60 miles south of Chicago, and be reserved for vehicles using electronic toll devices. It is expected to cost $1.5 billion.

Earl says the delay in federal approval also means other delays, including some property acquisitions and the issuance of a request for proposals soliciting private investors who want to build and operate the toll road. He says INDOT now forecasts it will be late summer or fall of next year at the earliest before construction can start.