Structure 5801380010400 · Merrimack County, NH

North Road over Smith River

Carries North Road over Smith River, .36 Mi. NW Jct. 104 And 4.

Overall conditionFair

Set by its lowest-rated component: Substructure at 6 of 9.

How ratings work
Deck7/9 · Good
Superstructure7/9 · Good
Substructuresets the rating6/9 · Satisfactory
Channelnot part of overall6/9 · Satisfactory
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
CAR · 15 FT46 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 7/9Superstructure 7/9Substructure 6/9 · sets the rating

46 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 multi-beam bridge.

Built1936rebuilt 1949
Length45.9 ft14 m
Daily traffic511counted 2023
Last inspectedMay 2024every 24 months

Location

StateNew Hampshire
CountyMerrimack
Location.36 Mi. NW Jct. 104 And 4
CarriesNorth Road
CrossesSmith River
Coordinates43.53111, -71.86232

Physical Characteristics

MaterialSteel
DesignStringer/Multi-beam
Total Length45.9 ft (14 m)
Max Span43.0 ft (13.1 m)
Deck Width24.0 ft (7.3 m)
Deck Area102.2 sq m
Main Spans1
Year Built1936 (reconstructed 1949)

Traffic

Avg Daily Traffic511 (2023)
Lanes On Bridge2

Inspection & Ownership

Last InspectionMay 2024
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is possibly eligible (requires evaluation)
Scour Critical8 — Stable, low risk
Structure Number005801380010400

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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