US Bridges

Main Street over Swift River

Fair

Carroll County, New Hampshire · 0.09 MI from Nh RTE 113 · Structure no. 025201120011400

Built
1973
52 years old
Condition
Fair
inspected October 2023
Type
Frame
Concrete
Length
74 ft
1 main span
Daily traffic
812
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

Main Street over Swift River is a concrete frame carrying Main Street over Swift River in Carroll County, New Hampshire. It was built in 1973, so it is 52 years old, younger than the New Hampshire average of 56.9 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 812 vehicles a day, roughly 4% of them trucks, projected to reach 1,201 by 2043. The structure is 74 ft (22.6 m) long and 36 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

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CarriesMain Street
CrossesSwift River
Location0.09 MI from Nh RTE 113
CountyCarroll County
StateNew Hampshire
Coordinates43.85969, -71.26461
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
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 evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating51 US tons
Inventory rating36 US tons

Structure

Structure typeFrame
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20 + Mod
Structure length74 ft (22.6 m)
Longest span66 ft (20.1 m)
Deck width36 ft (11.1 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic812 (2023)
Projected traffic1,201 by 2043
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$314,000 (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Main Street over Swift River built?

It was built in 1973, making it 52 years old in 2025.

What condition is Main Street over Swift 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 Main Street over Swift River carry?

About 812 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is Main Street over Swift River?

The structure is 74 ft (22.6 m) long with a longest span of 66 ft (20.1 m) and a deck 36 ft wide.

Who owns Main Street over Swift River?

It is owned by the City or Municipal Highway Agency.