Structure 5202030008800 · Merrimack County, NH

Nh 3a over I-93 Fee Tpk

Carries Nh 3a over I-93 Fee Tpk, 0.3 Mi N Of Bow Tl.

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
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT193 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 8/9Superstructure 8/9Substructure 8/9

193 ft end to end: about 3 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.

Built201511 years old
Length192.9 ft58.8 m
Daily traffic13,754counted 2023
Last inspectedMay 2023every 24 months

Location

StateNew Hampshire
CountyMerrimack
Location0.3 Mi N Of Bow Tl
CarriesNh 3a
CrossesI-93 Fee Tpk
Coordinates43.17984, -71.53096

Physical Characteristics

MaterialSteel
DesignStringer/Multi-beam
Total Length192.9 ft (58.8 m)
Max Span185.0 ft (56.4 m)
Deck Width55.1 ft (16.8 m)
Deck Area987.8 sq m
Main Spans1
Year Built2015

Traffic

Avg Daily Traffic13,754 (2023)
Truck Traffic5%
Lanes On Bridge2
Lanes Under Bridge4

Inspection & Ownership

Last InspectionMay 2023
Inspection FrequencyEvery 24 months
OwnerState Toll Authority
Historical SignificanceBridge is not eligible for the National Register
Scour CriticalNot applicable
Structure Number005202030008800

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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