US Bridges

Tri-County Highway over Flat Run

Fair

Brown County, Ohio · 8.42 MI E of Cler CO Line · Structure no. 0834815

Built
1956
69 years old
Condition
Fair
inspected December 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
140 ft
3 main spans
Daily traffic
1,423
2015 count
Owner
County
County Highway Agency

About this bridge

Tri-County Highway over Flat Run is a steel continuous stringer/multi-beam or girder carrying Tri-County Highway over Flat Run in Brown County, Ohio. It was built in 1956, so it is 69 years old, older than the Ohio average of 47.3 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 1,423 vehicles a day, roughly 8% of them trucks, projected to reach 1,975 by 2035. The structure is 140 ft (42.7 m) long and 36 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

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CarriesTri-County Highway
CrossesFlat Run
Location8.42 MI E of Cler CO Line
RouteCounty Highway C0024
CountyBrown County
StateOhio
Coordinates39.01657, -83.868
Functional classRural Major Collector

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionDecember 2024
Inspection intervalevery 12 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
Deck geometry6: Equal to present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating50 US tons
Inventory rating28.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadH 15
Structure length140 ft (42.7 m)
Longest span49 ft (14.9 m)
Deck width36 ft (11 m)
Roadway width36 ft (11 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,423 (2015)
Projected traffic1,975 by 2035
Trucks8%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Tri-County Highway over Flat Run built?

It was built in 1956, making it 69 years old in 2025.

What condition is Tri-County Highway over Flat Run 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 December 2024.

How much traffic does Tri-County Highway over Flat Run carry?

About 1,423 vehicles per day (2015 count), of which roughly 8% are trucks.

How long is Tri-County Highway over Flat Run?

The structure is 140 ft (42.7 m) long with a longest span of 49 ft (14.9 m) and a deck 36 ft wide.

Who owns Tri-County Highway over Flat Run?

It is owned by the County Highway Agency.