US Bridges

CR 421N over Flatrock River

Fair

Decatur County, Indiana · 00.50 N of CR 550 N · Structure no. 1600003

Built
1999
26 years old
Condition
Fair
inspected April 2023
Type
Tee Beam
Prestressed Concrete Continuous
Length
301 ft
3 main spans
Daily traffic
1,570
2017 count
Owner
County
County Highway Agency

About this bridge

CR 421N over Flatrock River is a prestressed concrete continuous tee beam carrying CR 421N over Flatrock River in Decatur County, Indiana. It was built in 1999, so it is 26 years old, younger than the Indiana average of 46.6 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 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 1,570 vehicles a day, roughly 10% of them trucks, projected to reach 2,460 by 2037. The structure is 301 ft (91.7 m) long and 33 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

Open in Google Maps
CarriesCR 421N
CrossesFlatrock River
Location00.50 N of CR 550 N
RouteCounty Highway 271
CountyDecatur County
StateIndiana
Coordinates39.42391, -85.59202
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating40.7 US tons
Inventory rating31.7 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length301 ft (91.7 m)
Longest span110 ft (33.5 m)
Deck width33 ft (10 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,570 (2017)
Projected traffic2,460 by 2037
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.8 mi (11 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 CR 421N over Flatrock River built?

It was built in 1999, making it 26 years old in 2025.

What condition is CR 421N over Flatrock River 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 2023.

How much traffic does CR 421N over Flatrock River carry?

About 1,570 vehicles per day (2017 count), of which roughly 10% are trucks.

How long is CR 421N over Flatrock River?

The structure is 301 ft (91.7 m) long with a longest span of 110 ft (33.5 m) and a deck 33 ft wide.

Who owns CR 421N over Flatrock River?

It is owned by the County Highway Agency.