In a move that has baffled and frustrated residents of 400 S Green Street, the Illinois Department of Transportation has apparently ruled out a version of the Circle Interchange expansion project that would avoid building a new, elevated highway ramp above Halsted Street. At an April 3 hearing on the project, IDOT told residents the option to avoid building the flyover, known as Alternative 15.4, was “off the table, not even being considered,” according to condo board president David Lewis.

Lewis said that during an earlier meeting in March with IDOT’s Paul Schneider, the agency said that Alternative 15.4 was still acceptable. Something else changed between the March meeting and the April meeting: IDOT added a lane to the westbound side of I-290 in Alternative 15.4.

Previously, the agency had always shown five lanes where westbound I-290 passes 400 S Green, as you can see in the map of 15.4 shown below. At the April meeting, the agency showed a drawing where that section of the highway had six lanes.

There are currently five lanes on I-290 next to 400 S Green, and the agency’s “preferred alternative” — which includes the Halsted flyover and would generate a lot of noise next to residences — also calls for five lanes on this section of the highway. Streetsblog has submitted multiple requests to IDOT seeking an explanation for the addition of the sixth lane in the option that doesn’t include building a flyover. The agency has not responded.

While today is the last day for public comment on the Circle Interchange project, the case of the extra highway lane raises serious questions about why IDOT has ruled out the version of the project without the Halsted flyover. Why was the sixth lane added? If the design without a flyover still called for five lanes, how would that change the cost of the project? Answers from IDOT have been in short supply.