US Bridges

Nh 9 over Mallego Brook

Fair

Strafford County, New Hampshire · 1.2MI from Barrington Tl · Structure no. 015900710010000

Built
1960
65 years old, rebuilt 1998
Condition
Fair
inspected April 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
54 ft
1 main span
Daily traffic
8,063
2023 count
Owner
State
State Highway Agency

About this bridge

Nh 9 over Mallego Brook is a steel stringer/multi-beam or girder carrying Nh 9 over Mallego Brook in Strafford County, New Hampshire. It was built in 1960 and reconstructed in 1998, so it is 65 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 8,063 vehicles a day, roughly 4% of them trucks, projected to reach 11,933 by 2043. The structure is 54 ft (16.5 m) long and 45 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

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CarriesNh 9
CrossesMallego Brook
Location1.2MI from Barrington Tl
RouteState Highway 9
CountyStrafford County
StateNew Hampshire
Coordinates43.19657, -70.95107
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionApril 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 rating49.3 US tons
Inventory rating29.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length54 ft (16.5 m)
Longest span47 ft (14.3 m)
Deck width45 ft (13.7 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic8,063 (2023)
Projected traffic11,933 by 2043
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 Nh 9 over Mallego Brook built?

It was built in 1960, making it 65 years old in 2025. It was reconstructed in 1998.

What condition is Nh 9 over Mallego 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 April 2023.

How much traffic does Nh 9 over Mallego Brook carry?

About 8,063 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is Nh 9 over Mallego Brook?

The structure is 54 ft (16.5 m) long with a longest span of 47 ft (14.3 m) and a deck 45 ft wide.

Who owns Nh 9 over Mallego Brook?

It is owned by the State Highway Agency.