Structure 17201550011500 · Hillsborough County, NH

Nh101 over Nh101a Csx

Carries Nh101 over Nh101a Csx, 0.2 Mi W. Amherst T.l..

Overall conditionFair

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

How ratings work
Deck7/9 · Good
Superstructuresets the rating5/9 · Fair
Substructure7/9 · Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT340 FT OVERALL50 FT0ELEVATION · LENGTHS TO SCALE
Deck 7/9Superstructure 5/9 · sets the ratingSubstructure 7/9

340 ft end to end, longest span 133 ft: about 5 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 multi-beam bridge.

Built197155 years old
Length339.9 ft103.6 m
Daily traffic15,196counted 2023
Last inspectedApril 2024every 24 months

Location

StateNew Hampshire
CountyHillsborough
Location0.2 Mi W. Amherst T.l.
CarriesNh101
CrossesNh101a Csx
Coordinates42.82474, -71.61728

Physical Characteristics

MaterialSteel Continuous
DesignStringer/Multi-beam
Total Length339.9 ft (103.6 m)
Max Span132.9 ft (40.5 m)
Deck Width51.8 ft (15.8 m)
Deck Area1636.9 sq m
Main Spans3
Year Built1971

Traffic

Avg Daily Traffic15,196 (2023)
Truck Traffic7%
Lanes On Bridge2
Lanes Under Bridge5

Inspection & Ownership

Last InspectionApril 2024
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is possibly eligible (requires evaluation)
Scour CriticalNot applicable
Structure Number017201550011500

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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