US Bridges

Western RD over Back River

Fair

Knox County, Maine · 1.8 MI SE JCT RTE 235 · Structure no. 3785

Built
1941
84 years old
Condition
Fair
inspected October 2023
Type
Slab
Concrete
Length
23 ft
1 main span
Daily traffic
2,180
2016 count
Owner
State
State Highway Agency

About this bridge

Western RD over Back River is a concrete slab carrying Western RD over Back River in Knox County, Maine. It was built in 1941, so it is 84 years old, older 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 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 2,180 vehicles a day, roughly 5% of them trucks, projected to reach 3,052 by 2036. The structure is 23 ft (7 m) long and 25 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

Open in Google Maps
CarriesWestern RD
CrossesBack River
Location1.8 MI SE JCT RTE 235
RouteCity Street 0
CountyKnox County
StateMaine
Coordinates44.15041, -69.27907
Functional classRural Local

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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 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 geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating52.5 US tons
Inventory rating40.3 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length23 ft (7 m)
Longest span20 ft (6.1 m)
Deck width25 ft (7.6 m)
Roadway width22 ft (6.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,180 (2016)
Projected traffic3,052 by 2036
Trucks5%
Lanes on structure2
Traffic directionTwo-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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Western RD over Back River built?

It was built in 1941, making it 84 years old in 2025.

What condition is Western RD over Back River 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 October 2023.

How much traffic does Western RD over Back River carry?

About 2,180 vehicles per day (2016 count), of which roughly 5% are trucks.

How long is Western RD over Back River?

The structure is 23 ft (7 m) long with a longest span of 20 ft (6.1 m) and a deck 25 ft wide.

Who owns Western RD over Back River?

It is owned by the State Highway Agency.