I-57 at I-74 Interchange Phase III, Champaign Co., Illinois

CLIENT: Illinois Department of Transportation (IDOT)

Clark Dietz is providing Phase III construction engineering services as a subconsultant for the reconstruction of the I-57/I-74 interchange west of Champaign. This multi-year program modernizes a critical regional freight junction that carries nearly 40,000 vehicles each day, approximately 25 percent of which are commercial trucks.

Originally designed in 1958 and constructed in 1965, the interchange’s outdated geometry contributes to congestion, merging and weaving conflicts, and reduced travel speeds. Four related construction projects address these challenges through improvements to the interchange’s ramps, structures, and adjoining roadways.

The reconstruction includes two flyover ramps connecting eastbound I-74 to northbound I-57 and westbound I-74 to southbound I-57. A third auxiliary lane in each direction of I-74 between Prospect Avenue and Duncan Road provides additional capacity and supports traffic movement through the corridor. The program encompasses 13 structures, extensive earthwork, pavement reconstruction, drainage improvements, ramp construction, lighting, and landscaping.

Clark Dietz’s services include construction inspection, documentation of pay quantities, on-site testing, material testing documentation, and verification of contractor staking and layout. Through these services, our team supports construction quality and conformance with project requirements.

Once complete, the reconstructed interchange will reduce merging and weaving movements, eliminate key conflict points, and improve safety, traffic flow, and travel times for motorists and freight carriers throughout the region.