I- 55 STEVENSON
I- 55 STEVENSON in 1.5 M W US 45, Cook County, Illinois received a condition grade of C (57/100). Built in 1963, the bridge carries 144K vehicles daily on I- 55 STEVENSON over Wolf RD & Flag CR.
I- 55 STEVENSON carries a C on the BridgeSafety Condition Score with 57/100. Component ratings sit in the middle of the FHWA NBI distribution; rehabilitation programming is likely on the owning agency’s medium-term horizon.
The bridge was built in 1963 and is now 63 years old, at or past the typical 50-year design life for bridges of its vintage. Maintenance and inspection cycles are correspondingly more involved than for newer structures. I- 55 STEVENSON carries an average daily traffic count of 144,200 vehicles, with 8 lane(s) crossing Wolf RD & Flag CR. The owning agency is State Highway Agency; bridge inspection records flow into the federal NBI database annually.
Component Ratings
The riding surface, evaluated for cracking, spalling, and wear
Beams, girders, and trusses that support the deck
Piers, abutments, and foundations below the deck
Bridge Details
About This Bridge
I- 55 STEVENSON is a 63-year-old bridge located 1.5 M W US 45 in Cook County, Illinois. The bridge carries I- 55 STEVENSON over Wolf RD & Flag CR with 8 traffic lanes, handling approximately 144K vehicles per day. Built in 1963 and reconstructed in 1996, the structure spans 86.1 meters.
The bridge received a Condition Grade of C (57/100) based on Federal Highway Administration inspection data. Its deck is rated 6/9 (fair), superstructure 5/9 (fair), and substructure 6/9 (fair).
This bridge is owned and maintained by State Highway Agency.
Location Map
Frequently Asked Questions
I- 55 STEVENSON has a Condition Score of 57/100 (Grade C). Its deck is rated 6/9, superstructure 5/9, and substructure 6/9 on the NBI scale. The bridge is not classified as structurally deficient.
I- 55 STEVENSON was built in 1963 and reconstructed in 1996, making it 63 years old. The average bridge age in the United States is 48 years.
I- 55 STEVENSON carries approximately 144K vehicles per day (average daily traffic). The bridge has 8 traffic lanes. It is 86.1 meters long and located on I- 55 STEVENSON in 1.5 M W US 45, Cook County, Illinois.
No, I- 55 STEVENSON is not classified as structurally deficient. All three primary components (deck, superstructure, and substructure) are rated above 4 on the 0-9 NBI scale.
I- 55 STEVENSON is located 1.5 M W US 45 in Cook County, Illinois. The bridge carries I- 55 STEVENSON over Wolf RD & Flag CR. Its coordinates are 41.760669, -87.896600. It is maintained by State Highway Agency.
I- 55 STEVENSON carries I- 55 STEVENSON over Wolf RD & Flag CR. The bridge is 86.1 meters long and was built in 1963, with reconstruction in 1996.
Condition Score is calculated from deck (33%), superstructure (33%), and substructure (34%) NBI ratings with an age penalty for bridges over 50 years.
Source: FHWA National Bridge Inventory, 2026.