US Bridges

I-89 NB over County Road

Good

Merrimack County, New Hampshire · 2.2 MI from Sutton T.L. · Structure no. 018800880007600

Built
1967
58 years old, rebuilt 1989
Condition
Good
inspected April 2023
Type
Frame
Concrete
Length
54 ft
1 main span
Daily traffic
9,751
2023 count
Owner
State
State Highway Agency

About this bridge

I-89 NB over County Road is a concrete frame carrying I-89 NB over County Road in Merrimack County, New Hampshire. It was built in 1967 and reconstructed in 1989, so it is 58 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 good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 9,751 vehicles a day, roughly 9% of them trucks, projected to reach 14,431 by 2043. The structure is 54 ft (16.5 m) long and 46 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

Location

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CarriesI-89 NB
CrossesCounty Road
Location2.2 MI from Sutton T.L.
RouteInterstate 89
CountyMerrimack County
StateNew Hampshire
Coordinates43.40218, -72.01725
Functional classRural Principal Arterial - Interstate

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating99 US tons
Inventory rating61.9 US tons

Structure

Structure typeFrame
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20 + Mod
Structure length54 ft (16.5 m)
Longest span46 ft (14 m)
Deck width46 ft (13.9 m)
Roadway width38 ft (11.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic9,751 (2023)
Projected traffic14,431 by 2043
Trucks9%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed9.9 mi (16 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$314,000 (2025 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-89 NB over County Road built?

It was built in 1967, making it 58 years old in 2025. It was reconstructed in 1989.

What condition is I-89 NB over County Road in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in April 2023.

How much traffic does I-89 NB over County Road carry?

About 9,751 vehicles per day (2023 count), of which roughly 9% are trucks.

How long is I-89 NB over County Road?

The structure is 54 ft (16.5 m) long with a longest span of 46 ft (14 m) and a deck 46 ft wide.

Who owns I-89 NB over County Road?

It is owned by the State Highway Agency.