Gray Plaza over Tributary Silver Creek
St. Clair County, Illinois · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Gray Plaza over Tributary Silver Creek in St. Clair County, Illinois, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the culvert, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1970, making it 55 years old at the 2025 inventory.
- It carries about 20 vehicles a day (traffic count year 2017).
- It is one of 205 of the 485 inventoried bridges in St. Clair County rated fair (42.3%); 45 (9.3%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its class is unchanged from 2024 (fair), but component ratings moved: culvert 6 to 5.
- Its most recent inspection on record is dated April 2024, on a 24-month routine inspection cycle.
- A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.
View this bridge on a map → (38.54958, -89.85106)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Culvert | 6 | 5 | Fair condition |
Bridge details
| Structure | Concrete culvert |
| Length | about 24 ft |
| Location | 130 N of Air Guard Way |
| NBI structure number | AFILVDYD00013 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | April 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 5: foundations stable, scour within the limits of the footing or piles |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Illinois department of transportation.
Busiest bridges in St. Clair County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Psb I-55 64;US 40 over Mississippi River | 1963 | 113,200 | Fair |
| I-55/64; US 40 Psc over Trra | 1966 | 113,200 | Poor |
| I-55/64; US 40 EB over 4TH ST in E ST LOU | 1965 | 105,300 | Fair |
| EB 55/MLK Eb&wb Ap over 3RD ST EXIT to EStL | 1961 | 105,300 | Good |
| I-55/70;/64 over Csxrr Nsrr Trrarr | 1959 | 66,500 | Poor |
| I-55/64EB mainlne" over UPRR IL 3 ramp UPRR UPRR | 1995 | 56,600 | Fair |
All bridges nearby: St. Clair County, IL bridge conditions · every bridge in St. Clair County · Illinois bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.