US Bridges

Sterling Highway over Cooper Creek

Fair

Kenai Peninsula Borough, Alaska · Mile Point 13.7 · Structure no. 0674

Built
1955
70 years old
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
68 ft
1 main span
Daily traffic
3,150
2020 count
Owner
State
State Highway Agency

About this bridge

Sterling Highway over Cooper Creek is a steel stringer/multi-beam or girder carrying Sterling Highway over Cooper Creek in Kenai Peninsula Borough, Alaska. It was built in 1955, so it is 70 years old, older than the Alaska average of 35.9 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 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 3,150 vehicles a day, roughly 14% of them trucks, projected to reach 4,090 by 2039. The structure is 68 ft (20.6 m) long and 27 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesSterling Highway
CrossesCooper Creek
LocationMile Point 13.7
RouteInterstate 0A33
CountyKenai Peninsula Borough
StateAlaska
Coordinates60.48417, -149.88083
Functional classRural 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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating45.7 US tons
Inventory rating27.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 15
Structure length68 ft (20.6 m)
Longest span64 ft (19.5 m)
Deck width27 ft (8.2 m)
Roadway width25 ft (7.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,150 (2020)
Projected traffic4,090 by 2039
Trucks14%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Sterling Highway over Cooper Creek built?

It was built in 1955, making it 70 years old in 2025.

What condition is Sterling Highway over Cooper 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 August 2023.

How much traffic does Sterling Highway over Cooper Creek carry?

About 3,150 vehicles per day (2020 count), of which roughly 14% are trucks.

How long is Sterling Highway over Cooper Creek?

The structure is 68 ft (20.6 m) long with a longest span of 64 ft (19.5 m) and a deck 27 ft wide.

Who owns Sterling Highway over Cooper Creek?

It is owned by the State Highway Agency.