US Bridges

Al - 75 over Blackburn Relief

Fair

Blount County, Alabama · .7 Mi. So. CO RD 15 · Structure no. 009752

Built
1968
57 years old
Condition
Fair
inspected June 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
371 ft
3 main spans
Daily traffic
4,105
2023 count
Owner
State
State Highway Agency

About this bridge

Al - 75 over Blackburn Relief is a steel continuous stringer/multi-beam or girder carrying Al - 75 over Blackburn Relief in Blount County, Alabama. It was built in 1968, so it is 57 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 4,105 vehicles a day, roughly 7% of them trucks, projected to reach 5,283 by 2043. The structure is 371 ft (113.1 m) long and 31 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

Open in Google Maps
CarriesAl - 75
CrossesBlackburn Relief
Location.7 Mi. So. CO RD 15
RouteU.S. Route 75
CountyBlount County
StateAlabama
Coordinates33.85248, -86.56648
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJune 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
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating48.7 US tons
Inventory rating29.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3 (+5 approach)
Design loadHS 20
Structure length371 ft (113.1 m)
Longest span80 ft (24.4 m)
Deck width31 ft (9.4 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,105 (2023)
Projected traffic5,283 by 2043
Trucks7%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$2.8 million (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Al - 75 over Blackburn Relief built?

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

What condition is Al - 75 over Blackburn Relief 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 June 2023.

How much traffic does Al - 75 over Blackburn Relief carry?

About 4,105 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is Al - 75 over Blackburn Relief?

The structure is 371 ft (113.1 m) long with a longest span of 80 ft (24.4 m) and a deck 31 ft wide.

Who owns Al - 75 over Blackburn Relief?

It is owned by the State Highway Agency.