IDOT lists I-80 reconstruction at Illinois 251 interchange in Peru

Drivers using the I-80 and Illinois 251 interchange in Peru, LaSalle County, are dealing with active bridge repairs while the Illinois Department of Transportation continues preliminary engineering for a broader interchange reconstruction project.

The near-term effect is already in place. IDOT began work July 13, 2026, on the bridges carrying Illinois 251 over I-80. One Illinois 251 lane remains open in each direction, and occasional lane closures on I-80 are expected. The separate bridge-repair project costs $1.8 million and is expected to be completed in fall 2026.

Bridge repairs are separate from interchange planning

The active repairs include deck patching and resurfacing, removal and replacement of bridge bearings and expansion joints, and shoulder repairs. IDOT has warned motorists to expect delays and allow additional time through the work area.

That work should not be confused with the larger interchange reconstruction effort. IDOT’s FY 2026-2027 Statewide Transportation Improvement Program lists I-80 at Illinois 251 in Peru under project ID 263407000011 for fiscal year 2026 and project ID 273407000012 for fiscal year 2027. Each entry lists $3.5 million in state-only funding for P.E. Phase I.

P.E. Phase I means preliminary engineering. The programmed money supports planning and design work; it is not an appropriation for construction of a completed interchange design, and it should not be treated as the final cost of reconstruction.

Study area extends beyond the interchange

In a 2025 consultant-services bulletin, IDOT described the broader assignment as Phase I/II engineering for reconstruction of the I-80 interchange with Illinois 251 at Peru.

The evaluation area described in the bulletin includes I-80 from the Little Vermilion River to just east of Plank Road; Illinois 251 from south of 31st Road to 38th Street; and portions of May Road and Charles Street that are unmarked state routes. The evaluation limits describe the area engineers will study; they do not establish that every listed segment will ultimately be reconstructed.

The planned engineering work is intended to produce a combined design report and, through Phase II, final contract plans, specifications and estimates. The bulletin also identifies possible work involving interchange and intersection studies, bridge-condition reports, traffic and safety analysis, drainage and utility reviews, public-involvement materials, and traffic-management planning.

What the records do not establish

The available records show that the larger interchange project is planned, programmed for Phase I engineering and under study. They do not establish a construction start date, a final interchange configuration, a right-of-way acquisition schedule or a final construction price.

They also do not show that full interchange reconstruction will begin in 2026. For now, Illinois 251 travelers should plan for the active bridge repairs and possible I-80 lane closures through fall, while commuters, freight operators and nearby businesses should treat the broader reconstruction as an engineering and design project rather than current construction.

Sources

• Illinois Department of Transportation: Illinois 251 bridge repairs in Peru begins July 13
• IDOT FY 2026-2027 Statewide Transportation Improvement Program