Structure 11201250004900 · Hillsborough County, NH

Tannery Hill Road over Ferguson Brook

Carries Tannery Hill Road over Ferguson Brook, 0.5 Mi From Middle Road.

Overall conditionGood

Set by its lowest-rated component: Deck and Superstructure and Substructure at 8 of 9.

How ratings work
Decksets the rating8/9 · Very Good
Superstructuresets the rating8/9 · Very Good
Substructuresets the rating8/9 · Very Good
Channelnot part of overall8/9 · Very Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
CAR · 15 FT31 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 8/9Superstructure 8/9Substructure 8/9

31 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 slab bridge.

Built200224 years old
Length30.8 ft9.4 m
Daily traffic226counted 2023
Last inspectedAugust 2024every 24 months

Location

StateNew Hampshire
CountyHillsborough
Location0.5 Mi From Middle Road
CarriesTannery Hill Road
CrossesFerguson Brook
Coordinates42.93971, -71.96605

Physical Characteristics

MaterialConcrete
DesignSlab
Total Length30.8 ft (9.4 m)
Max Span27.9 ft (8.5 m)
Deck Width26.9 ft (8.2 m)
Deck Area77.1 sq m
Main Spans1
Year Built2002

Traffic

Avg Daily Traffic226 (2023)
Truck Traffic4%
Lanes On Bridge2

Inspection & Ownership

Last InspectionAugust 2024
Inspection FrequencyEvery 24 months
OwnerCity/Municipal Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical8 — Stable, low risk
Structure Number011201250004900

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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