Structure 2100960008700 · Hillsborough County, NH

Nh 31 over Contoocook River

Carries Nh 31 over Contoocook River, 1.24 Mi. NE Hancock Tl.

Overall conditionFair

Set by its lowest-rated component: Deck and Superstructure at 5 of 9.

How ratings work
Decksets the rating5/9 · Fair
Superstructuresets the rating5/9 · Fair
Substructure7/9 · Good
Channelnot part of overall7/9 · Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
CAR · 15 FT89 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 5/9 · sets the ratingSuperstructure 5/9 · sets the ratingSubstructure 7/9

89 ft end to end. Lengths and the car on the deck are drawn to the same scale. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a rigid-frame bridge.

Built193492 years old
Length88.9 ft27.1 m
Daily traffic1,693counted 2023
Last inspectedMay 2024every 24 months

Location

StateNew Hampshire
CountyHillsborough
Location1.24 Mi. NE Hancock Tl
CarriesNh 31
CrossesContoocook River
Coordinates43.00143, -71.92562

Physical Characteristics

MaterialConcrete
DesignFrame
Total Length88.9 ft (27.1 m)
Max Span80.1 ft (24.4 m)
Deck Width34.1 ft (10.4 m)
Deck Area281.8 sq m
Main Spans1
Year Built1934

Traffic

Avg Daily Traffic1,693 (2023)
Truck Traffic4%
Lanes On Bridge2

Inspection & Ownership

Last InspectionMay 2024
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is eligible for the National Register
Scour Critical8 — Stable, low risk
Structure Number002100960008700

How Bridge Ratings Work

Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."

0Failed
1Imminent failure
2Critical
3Serious
4Poor
5Fair
6Satisfactory
7Good
8Very good
9Excellent
Good · lowest component 7–9
Fair · lowest component 5–6
Poor · lowest component 0–4

A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.

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