US Bridges

US 421 over I-71

Fair

Henry County, Kentucky · 1.6 MI N of Ky 997 · Structure no. 052B00038N

Built
1968
57 years old
Condition
Fair
inspected July 2023
Type
Tee Beam
Concrete
Length
294 ft
6 main spans
Daily traffic
3,181
2020 count
Owner
State
State Highway Agency

About this bridge

US 421 over I-71 is a concrete tee beam carrying US 421 over I-71 in Henry County, Kentucky. It was built in 1968, so it is 57 years old, older than the Kentucky 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 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 3,181 vehicles a day, projected to reach 3,181 by 2040. The structure is 294 ft (89.6 m) long and 36 ft wide. If it were closed, the detour would be 8.7 mi (14 km).

Location

Open in Google Maps
CarriesUS 421
CrossesI-71
Location1.6 MI N of Ky 997
RouteU.S. Route 421
CountyHenry County
StateKentucky
Coordinates38.52083, -85.23417
Functional classRural Minor Arterial

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating68.9 US tons
Inventory rating41.4 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans6
Design loadHS 20
Structure length294 ft (89.6 m)
Longest span49 ft (14.9 m)
Deck width36 ft (10.9 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,181 (2020)
Projected traffic3,181 by 2040
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed8.7 mi (14 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was US 421 over I-71 built?

It was built in 1968, making it 57 years old in 2025.

What condition is US 421 over I-71 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 July 2023.

How much traffic does US 421 over I-71 carry?

About 3,181 vehicles per day (2020 count).

How long is US 421 over I-71?

The structure is 294 ft (89.6 m) long with a longest span of 49 ft (14.9 m) and a deck 36 ft wide.

Who owns US 421 over I-71?

It is owned by the State Highway Agency.