Structure 2302380005500 · Coos County, NH

Mason Street over Canal

Carries Mason Street over Canal, 610ft West Of Unity ST.

Overall conditionFair

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

How ratings work
Decksets the rating6/9 · Satisfactory
Superstructure7/9 · Good
Substructure7/9 · Good
Channelnot part of overall7/9 · Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT121 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 6/9 · sets the ratingSuperstructure 7/9Substructure 7/9

121 ft end to end, longest span 58 ft. 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.

Built1967rebuilt 1977
Length121.1 ft36.9 m
Daily traffic3,538counted 2023
Last inspectedOctober 2024every 24 months

Location

StateNew Hampshire
CountyCoos
Location610ft West Of Unity ST
CarriesMason Street
CrossesCanal
Coordinates44.46970, -71.17926

Physical Characteristics

MaterialSteel
DesignStringer/Multi-beam
Total Length121.1 ft (36.9 m)
Max Span58.1 ft (17.7 m)
Deck Width37.1 ft (11.3 m)
Deck Area417.0 sq m
Main Spans2
Year Built1967 (reconstructed 1977)

Traffic

Avg Daily Traffic3,538 (2023)
Truck Traffic5%
Lanes On Bridge2

Inspection & Ownership

Last InspectionOctober 2024
Inspection FrequencyEvery 24 months
OwnerCity/Municipal Highway Agency
Historical SignificanceBridge is possibly eligible (requires evaluation)
Scour Critical8 — Stable, low risk
Structure Number002302380005500

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