US Bridges

Flat Branch RD-TR1 over US 50

Good

Clinton County, Illinois · 1.5 MI W of Carlyle · Structure no. 014005600000000

Built
1973
52 years old
Condition
Good
inspected July 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
226 ft
2 main spans
Daily traffic
400
2020 count
Owner
State
State Highway Agency

About this bridge

Flat Branch RD-TR1 over US 50 is a steel continuous stringer/multi-beam or girder carrying Flat Branch RD-TR1 over US 50 in Clinton County, Illinois. It was built in 1973, so it is 52 years old, older than the Illinois average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 400 vehicles a day, roughly 7% of them trucks, projected to reach 440 by 2046. The structure is 226 ft (68.9 m) long and 30 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

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CarriesFlat Branch RD-TR1
CrossesUS 50
Location1.5 MI W of Carlyle
RouteCounty Highway 0
CountyClinton County
StateIllinois
Coordinates38.62395, -89.40081
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure8 Very GoodNo problems noted.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating45.3 US tons
Inventory rating30 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans2 (+2 approach)
Design loadHS 15
Structure length226 ft (68.9 m)
Longest span93 ft (28.3 m)
Deck width30 ft (9.1 m)
Roadway width27 ft (8.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic400 (2020)
Projected traffic440 by 2046
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed6.2 mi (10 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was Flat Branch RD-TR1 over US 50 built?

It was built in 1973, making it 52 years old in 2025.

What condition is Flat Branch RD-TR1 over US 50 in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in July 2023.

How much traffic does Flat Branch RD-TR1 over US 50 carry?

About 400 vehicles per day (2020 count), of which roughly 7% are trucks.

How long is Flat Branch RD-TR1 over US 50?

The structure is 226 ft (68.9 m) long with a longest span of 93 ft (28.3 m) and a deck 30 ft wide.

Who owns Flat Branch RD-TR1 over US 50?

It is owned by the State Highway Agency.