US Bridges

I - 20 West over US 78 (AL-4)

Fair

Jefferson County, Alabama · I 20 * US 78 · Structure no. 011070

Built
1974
51 years old, rebuilt 1989
Condition
Fair
inspected September 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
1,010 ft
10 main spans
Daily traffic
27,875
2024 count
Owner
State
State Highway Agency

About this bridge

I - 20 West over US 78 (AL-4) is a steel stringer/multi-beam or girder carrying I - 20 West over US 78 (AL-4) in Jefferson County, Alabama. It was built in 1974 and reconstructed in 1989, so it is 51 years old, younger 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 27,875 vehicles a day, roughly 16% of them trucks, projected to reach 33,677 by 2044. The structure is 1,010 ft (307.8 m) long and 55 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI - 20 West
CrossesUS 78 (AL-4)
LocationI 20 * US 78
RouteInterstate 20
CountyJefferson County
StateAlabama
Coordinates33.53097, -86.71306
Functional classUrban Principal Arterial - Interstate

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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2024
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 geometry6: Equal to present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating84.8 US tons
Inventory rating50.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans10
Design loadHS 20
Structure length1,010 ft (307.8 m)
Longest span105 ft (32 m)
Deck width55 ft (16.9 m)
Roadway width53 ft (16.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic27,875 (2024)
Projected traffic33,677 by 2044
Trucks16%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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$12.8 million (2025 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I - 20 West over US 78 (AL-4) built?

It was built in 1974, making it 51 years old in 2025. It was reconstructed in 1989.

What condition is I - 20 West over US 78 (AL-4) 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 2024.

How much traffic does I - 20 West over US 78 (AL-4) carry?

About 27,875 vehicles per day (2024 count), of which roughly 16% are trucks.

How long is I - 20 West over US 78 (AL-4)?

The structure is 1,010 ft (307.8 m) long with a longest span of 105 ft (32 m) and a deck 55 ft wide.

Who owns I - 20 West over US 78 (AL-4)?

It is owned by the State Highway Agency.