Structure 27900820008700 · Cheshire County, NH

Gunn Mountain Road over Ashuelot River

Carries Gunn Mountain Road over Ashuelot River, 0.02mi Nh119.

Overall conditionGood

Set by its lowest-rated component: Deck and Superstructure and Substructure at 7 of 9.

How ratings work
Decksets the rating7/9 · Good
Superstructuresets the rating7/9 · Good
Substructuresets the rating7/9 · Good
Channelnot part of overall7/9 · Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT173 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 7/9Superstructure 7/9Substructure 7/9

173 ft end to end, longest span 84 ft: about 2 semi-trucks nose to tail. Lengths and the semi-truck 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 through truss.

Built1864rebuilt 1999
Length173.2 ft52.8 m
Daily traffic821counted 2023
Last inspectedAugust 2024every 24 months

Location

StateNew Hampshire
CountyCheshire
Location0.02mi Nh119
CarriesGunn Mountain Road
CrossesAshuelot River
Coordinates42.77716, -72.42333

Physical Characteristics

MaterialWood or Timber
DesignTruss - Thru
Total Length173.2 ft (52.8 m)
Max Span84.3 ft (25.7 m)
Deck Width26.6 ft (8.1 m)
Deck Area427.7 sq m
Main Spans2
Year Built1864 (reconstructed 1999)

Traffic

Avg Daily Traffic821 (2023)
Truck Traffic4%
Lanes On Bridge1

Inspection & Ownership

Last InspectionAugust 2024
Inspection FrequencyEvery 24 months
OwnerCity/Municipal Highway Agency
Historical SignificanceBridge is eligible for the National Register
Scour Critical7 — Countermeasures installed
Structure Number027900820008700

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.

Nearby Bridges