Structure 16101280012600 · Hillsborough County, NH

I-93 NB over Bridge Street

Carries I-93 NB over Bridge Street, 1.2 Mi W Jct Nh 28 Byp.

Overall conditionFair

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

How ratings work
Deck8/9 · Very Good
Superstructure7/9 · Good
Substructuresets the rating6/9 · Satisfactory
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
CAR · 15 FT85 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 8/9Superstructure 7/9Substructure 6/9 · sets the rating

85 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.

Built1977rebuilt 1999
Length85.0 ft25.9 m
Daily traffic25,082counted 2023
Last inspectedApril 2023every 24 months

Location

StateNew Hampshire
CountyHillsborough
Location1.2 Mi W Jct Nh 28 Byp
CarriesI-93 NB
CrossesBridge Street
Coordinates42.99374, -71.41594

Physical Characteristics

MaterialSteel
DesignStringer/Multi-beam
Total Length85.0 ft (25.9 m)
Max Span80.1 ft (24.4 m)
Deck Width62.7 ft (19.1 m)
Deck Area494.7 sq m
Main Spans1
Year Built1977 (reconstructed 1999)

Traffic

Avg Daily Traffic25,082 (2023)
Truck Traffic6%
Lanes On Bridge3
Lanes Under Bridge4

Inspection & Ownership

Last InspectionApril 2023
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour CriticalNot applicable
Structure Number016101280012600

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