US-421 over Mills Branch
PoorPosted for loadHarlan County, Kentucky · 1.0 MI East of JCT Ky 568 · Structure no. 048B00024N
- Built
- 1934
- 91 years old
- Condition
- Poor
- inspected June 2023
- Type
- Culvert
- Concrete
- Length
- 20 ft
- 2 main spans
- Daily traffic
- 1,251
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
US-421 over Mills Branch is a concrete culvert carrying US-421 over Mills Branch in Harlan County, Kentucky. It was built in 1934, so it is 91 years old, older than the Kentucky average of 46.6 years.
The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. Its operating status is: posted for load restriction.
It carries about 1,251 vehicles a day, roughly 20% of them trucks, projected to reach 1,251 by 2043. The structure is 20 ft (6.1 m) long. If it were closed, the detour would be 55.3 mi (89 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.
| Component | Rating | Meaning |
|---|---|---|
| Channel and channel protection | 6 Satisfactory | Structural elements show some minor deterioration. |
| Culvert | 4 Poor | Advanced section loss, deterioration, spalling or scour. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was US-421 over Mills Branch built?
It was built in 1934, making it 91 years old in 2025.
What condition is US-421 over Mills Branch in?
The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in June 2023.
How much traffic does US-421 over Mills Branch carry?
About 1,251 vehicles per day (2023 count), of which roughly 20% are trucks.
How long is US-421 over Mills Branch?
The structure is 20 ft (6.1 m) long with a longest span of 8 ft (2.4 m).
Who owns US-421 over Mills Branch?
It is owned by the State Highway Agency.