US Bridges

SR21 over Mill Creek

Fair

Calhoun County, Alabama · City of Piedmont · Structure no. 006725

Built
1959
66 years old
Condition
Fair
inspected September 2023
Type
Culvert
Concrete
Length
58 ft
4 main spans
Daily traffic
3,653
2022 count
Owner
State
State Highway Agency

About this bridge

SR21 over Mill Creek is a concrete culvert carrying SR21 over Mill Creek in Calhoun County, Alabama. It was built in 1959, so it is 66 years old, older than the Alabama average of 51.1 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 3,653 vehicles a day, roughly 4% of them trucks, projected to reach 5,114 by 2042. The structure is 58 ft (17.6 m) long. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesSR21
CrossesMill Creek
LocationCity of Piedmont
RouteState Highway 21
CountyCalhoun County
StateAlabama
Coordinates33.9244, -85.62518
Functional classRural Principal Arterial - Other

Condition and inspection

Fair

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

ComponentRatingMeaning
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating98 US tons
Inventory rating98 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans4
Design loadHS 20
Structure length58 ft (17.6 m)
Longest span14 ft (4.2 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,653 (2022)
Projected traffic5,114 by 2042
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$1.2 million (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR21 over Mill Creek built?

It was built in 1959, making it 66 years old in 2025.

What condition is SR21 over Mill Creek 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 September 2023.

How much traffic does SR21 over Mill Creek carry?

About 3,653 vehicles per day (2022 count), of which roughly 4% are trucks.

How long is SR21 over Mill Creek?

The structure is 58 ft (17.6 m) long with a longest span of 14 ft (4.2 m).

Who owns SR21 over Mill Creek?

It is owned by the State Highway Agency.