US Bridges

Antrim Road over Contoocook River

Fair

Hillsborough County, New Hampshire · 0.05 MI FR Contoocook Va · Structure no. 002100880009500

Built
1929
96 years old
Condition
Fair
inspected November 2023
Type
Arch - Deck
Concrete
Length
144 ft
1 main span
Daily traffic
2,233
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

Antrim Road over Contoocook River is a concrete arch - deck carrying Antrim Road over Contoocook River in Hillsborough County, New Hampshire. It was built in 1929, so it is 96 years old, older 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 2,233 vehicles a day, roughly 4% of them trucks, projected to reach 3,304 by 2043. The structure is 144 ft (43.9 m) long and 28 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

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CarriesAntrim Road
CrossesContoocook River
Location0.05 MI FR Contoocook Va
CountyHillsborough County
StateNew Hampshire
Coordinates43.00831, -71.93195
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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be 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 rating24 US tons
Inventory rating17 US tons

Structure

Structure typeArch - Deck
MaterialConcrete
DeckNot applicable
Main spans1
Design loadH 15
Structure length144 ft (43.9 m)
Longest span108 ft (32.9 m)
Deck width28 ft (8.5 m)
Roadway width25 ft (7.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,233 (2023)
Projected traffic3,304 by 2043
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusEligible for the National Register of Historic Places
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 Antrim Road over Contoocook River built?

It was built in 1929, making it 96 years old in 2025.

What condition is Antrim Road over Contoocook 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 November 2023.

How much traffic does Antrim Road over Contoocook River carry?

About 2,233 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is Antrim Road over Contoocook River?

The structure is 144 ft (43.9 m) long with a longest span of 108 ft (32.9 m) and a deck 28 ft wide.

Who owns Antrim Road over Contoocook River?

It is owned by the City or Municipal Highway Agency.