US Bridges

Market Street over Grant Brook

Fair

Grafton County, New Hampshire · 4.0 MI FR Hanover Tl · Structure no. 015700840010500

Built
1974
51 years old
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
28 ft
1 main span
Daily traffic
72
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

Market Street over Grant Brook is a steel stringer/multi-beam or girder carrying Market Street over Grant Brook in Grafton County, New Hampshire. It was built in 1974, so it is 51 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 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 72 vehicles a day, roughly 4% of them trucks, projected to reach 106 by 2043. The structure is 28 ft (8.5 m) long and 24 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

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CarriesMarket Street
CrossesGrant Brook
Location4.0 MI FR Hanover Tl
CountyGrafton County
StateNew Hampshire
Coordinates43.80653, -72.15272
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionAugust 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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating25.2 US tons
Inventory rating18 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadUnknown
Structure length28 ft (8.5 m)
Longest span24 ft (7.3 m)
Deck width24 ft (7.4 m)
Roadway width22 ft (6.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic72 (2023)
Projected traffic106 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

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 Market Street over Grant Brook built?

It was built in 1974, making it 51 years old in 2025.

What condition is Market Street over Grant 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 August 2023.

How much traffic does Market Street over Grant Brook carry?

About 72 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is Market Street over Grant Brook?

The structure is 28 ft (8.5 m) long with a longest span of 24 ft (7.3 m) and a deck 24 ft wide.

Who owns Market Street over Grant Brook?

It is owned by the City or Municipal Highway Agency.