Construction on the Kennedy Expressway is set to begin Monday, likely causing major delays for drivers for nearly three years.

The $150 million project will take place along a 7.5-mile stretch from the split at I-94 south to Ohio Street, and at the massive underpass near Hubbard Street downtown. It will include rehabbing 36 bridges and the highway’s reversible express lane access system, replacing overhead signs, upgrading lighting, paving and painting.

The work is designed to improve safety, traffic flow and reliability on the 10-lane expressway, used by more than 275,000 drivers each day, the Illinois Department of Transportation said. The last major rehabilitation of the 63-year-old roadway was in 1994, and bridges were last repaired a decade ago.

Construction is expected to take place in phases over the next three warm-weather seasons, starting with the inbound, or southbound, lanes this year.

Two regular inbound lanes will be closed at a time, and drivers will also encounter lane shifts and some exit ramp closures. The reversible express lanes in the center of the highway will remain open in the inbound direction, but IDOT cautioned drivers that not every exit is available from the express lanes.

Later in 2023, work will begin to paint and install new LED lighting at the large Hubbard Street underpass between Ohio and Lake streets, known as Hubbard’s Cave.

All inbound lanes and ramps are expected to reopen in the fall, when the reversible express lanes are also expected to resume typical operations.

Construction will move to the reversible express lanes in spring 2024, which will remain closed while bridges and the express lane access system are rehabilitated and pavement is patched. Some regular, non-express lanes will also remain closed while lighting installation and painting continues at Hubbard’s Cave.

In spring 2025, work is set to begin on the outbound lanes, where two will be closed at a time, lanes will shift and some ramps will close. The express lanes in the center of the highway will remain open in the outbound direction.

The outbound work and the updates at Hubbard’s Cave are expected to be complete in late fall 2025.

Crews will begin setting up the first work zone next week, reducing the inbound Kennedy to two lanes. They will put up barriers from the north end of the construction zone, near the I-94 split, and move south to Ohio Street, working overnight from 10 p.m. to 5 a.m.

The setup is expected to take about one week.

IDOT warned drivers should expect “major travel delays” throughout construction, and encouraged drivers to take alternate routes, travel during nonpeak hours or use public transportation.

As the construction is set to begin, Metra is planning to add weekday trains to its Union Pacific Northwest Line, which runs alongside the Kennedy Expressway for much of the stretch that will be under construction. The new schedule will include 12 additional weekday trains during peak and off-peak hours, Metra Executive Director Jim Derwinski said in a statement, meaning trains will run at least every 30 minutes during rush hour and hourly at most stations at other times.

The schedule changes, which will take place April 3, are largely in response to ridership trends and customer feedback, but also provide an alternate route during the expressway construction, he said.

“With a major multiyear rehab project scheduled to start on the Kennedy Expressway, this new schedule allows Metra to provide more commuters with a viable and much less stressful alternative to driving,” Derwinski said.

sfreishtat@chicagotribune.com