ABC7 spotted orange barrels in place early Tuesday morning, ready to block lanes.
The project will impact both directions of the Bishop Ford between Martin Luther King Drive to U.S. 6 (159th Street).
Crews will be patching and resurfacing 9.5 miles, replacing overhead signs, installing LED lights, and rehabbing bridges.
IDOT says throughout the day on Tuesday into the overnight hours outbound Bishop Ford will be reduced from three lanes to two lanes from south of 130th Street to U.S. 6.
The outbound Bishop Ford ramp to eastbound Dolton Avenue and the westbound 159th Street ramp to the outbound Bishop Ford also will close.
All are expected to reopen in December, IDOT said.
Crews won't start working on the inbound side of the Bishop Ford until spring of next year.
In the meantime, drivers who typically take the Ford should start planning for alternate routes to work, or expect heavy, heavy delays.
State officials say this is all to keep drivers safe and roadways up-to-date and reliable.
The Michigan City Road bridge over the Bishop Ford is expected to close in August, it should be reopened by the end of the year.
The Bishop Ford Freeway, originally named the Calumet Expressway, opened in 1950, and had its last major rehabilitation in 2015.
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