US Bridges

Gray Plaza over Tributary Silver Creek

Fair

St. Clair County, Illinois · 130 N of Air Guard Way · Structure no. AFILVDYD00013

Built
1970
55 years old
Condition
Fair
inspected April 2024
Type
Culvert
Concrete
Length
25 ft
2 main spans
Daily traffic
20
2017 count
Owner
Federal
Air Force

About this bridge

Gray Plaza over Tributary Silver Creek is a concrete culvert carrying Gray Plaza over Tributary Silver Creek in St. Clair County, Illinois. It was built in 1970, so it is 55 years old, older than the Illinois average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 20 vehicles a day, projected to reach 25 by 2037. The structure is 25 ft (7.6 m) long. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesGray Plaza
CrossesTributary Silver Creek
Location130 N of Air Guard Way
RouteFederal Lands Road 0
CountySt. Clair County
StateIllinois
Coordinates38.54958, -89.85106
Functional classUrban Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating40 US tons
Inventory rating36 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans2
Design loadUnknown
Structure length25 ft (7.6 m)
Longest span12 ft (3.7 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic20 (2017)
Projected traffic25 by 2037
Trucks—
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerAir Force
Maintained byAir Force
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost$45,000 (2021 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Gray Plaza over Tributary Silver Creek built?

It was built in 1970, making it 55 years old in 2025.

What condition is Gray Plaza over Tributary Silver Creek in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in April 2024.

How much traffic does Gray Plaza over Tributary Silver Creek carry?

About 20 vehicles per day (2017 count).

How long is Gray Plaza over Tributary Silver Creek?

The structure is 25 ft (7.6 m) long with a longest span of 12 ft (3.7 m).

Who owns Gray Plaza over Tributary Silver Creek?

It is owned by the Air Force.