US Bridges

Brook Road over Brock Brook

Fair

Grafton County, New Hampshire · 0.3 MI FR Shin Valley RD · Structure no. 000301000011600

Built
1930
95 years old, rebuilt 2004
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
42 ft
1 main span
Daily traffic
96
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

Brook Road over Brock Brook is a steel stringer/multi-beam or girder carrying Brook Road over Brock Brook in Grafton County, New Hampshire. It was built in 1930 and reconstructed in 2004, so it is 95 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 96 vehicles a day, roughly 4% of them trucks, projected to reach 142 by 2043. The structure is 42 ft (12.7 m) long and 22 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

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CarriesBrook Road
CrossesBrock Brook
Location0.3 MI FR Shin Valley RD
CountyGrafton County
StateNew Hampshire
Coordinates43.63942, -71.84884
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 protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 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 adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating43.7 US tons
Inventory rating37.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckWood or timber
Main spans1
Design loadUnknown
Structure length42 ft (12.7 m)
Longest span35 ft (10.7 m)
Deck width22 ft (6.6 m)
Roadway width21 ft (6.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic96 (2023)
Projected traffic142 by 2043
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
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 Brook Road over Brock Brook built?

It was built in 1930, making it 95 years old in 2025. It was reconstructed in 2004.

What condition is Brook Road over Brock 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 Brook Road over Brock Brook carry?

About 96 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is Brook Road over Brock Brook?

The structure is 42 ft (12.7 m) long with a longest span of 35 ft (10.7 m) and a deck 22 ft wide.

Who owns Brook Road over Brock Brook?

It is owned by the City or Municipal Highway Agency.