US Bridges

Fort Knox RD over Carley Brook

Fair

Waldo County, Maine · 0.4 MI E of JCT US1A · Structure no. 2510

Built
1979
46 years old
Condition
Fair
inspected November 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
61 ft
1 main span
Daily traffic
1,796
2016 count
Owner
State
State Highway Agency

About this bridge

Fort Knox RD over Carley Brook is a steel stringer/multi-beam or girder carrying Fort Knox RD over Carley Brook in Waldo County, Maine. It was built in 1979, so it is 46 years old, younger than the Maine average of 53.7 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 1,796 vehicles a day, roughly 5% of them trucks, projected to reach 2,694 by 2036. The structure is 61 ft (18.6 m) long and 36 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

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CarriesFort Knox RD
CrossesCarley Brook
Location0.4 MI E of JCT US1A
RouteState Highway 174
CountyWaldo County
StateMaine
Coordinates44.55616, -68.85791
Functional classRural Major Collector

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating94.7 US tons
Inventory rating73.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20 + Mod
Structure length61 ft (18.6 m)
Longest span55 ft (16.8 m)
Deck width36 ft (11.1 m)
Roadway width33 ft (10.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,796 (2016)
Projected traffic2,694 by 2036
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.8 mi (11 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Fort Knox RD over Carley Brook built?

It was built in 1979, making it 46 years old in 2025.

What condition is Fort Knox RD over Carley Brook 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 November 2024.

How much traffic does Fort Knox RD over Carley Brook carry?

About 1,796 vehicles per day (2016 count), of which roughly 5% are trucks.

How long is Fort Knox RD over Carley Brook?

The structure is 61 ft (18.6 m) long with a longest span of 55 ft (16.8 m) and a deck 36 ft wide.

Who owns Fort Knox RD over Carley Brook?

It is owned by the State Highway Agency.