US Bridges

I-93 NB over Nh 49

Good

Grafton County, New Hampshire · 1.4MI from Thornton Tl · Structure no. 003501410013300

Built
1968
57 years old, rebuilt 2002
Condition
Good
inspected April 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
90 ft
1 main span
Daily traffic
7,498
2023 count
Owner
State
State Highway Agency

About this bridge

I-93 NB over Nh 49 is a steel stringer/multi-beam or girder carrying I-93 NB over Nh 49 in Grafton County, New Hampshire. It was built in 1968 and reconstructed in 2002, so it is 57 years old, older than the New Hampshire average of 56.9 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 7,498 vehicles a day, roughly 10% of them trucks, projected to reach 11,097 by 2043. The structure is 90 ft (27.4 m) long and 44 ft wide. If it were closed, the detour would be 14.3 mi (23 km).

Location

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CarriesI-93 NB
CrossesNh 49
Location1.4MI from Thornton Tl
RouteInterstate 93
CountyGrafton County
StateNew Hampshire
Coordinates43.85088, -71.64587
Functional classRural Principal Arterial - Interstate

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating62.1 US tons
Inventory rating45 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 25 or greater
Structure length90 ft (27.4 m)
Longest span85 ft (25.9 m)
Deck width44 ft (13.3 m)
Roadway width39 ft (12 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,498 (2023)
Projected traffic11,097 by 2043
Trucks10%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed14.3 mi (23 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$314,000 (2025 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-93 NB over Nh 49 built?

It was built in 1968, making it 57 years old in 2025. It was reconstructed in 2002.

What condition is I-93 NB over Nh 49 in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in April 2023.

How much traffic does I-93 NB over Nh 49 carry?

About 7,498 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is I-93 NB over Nh 49?

The structure is 90 ft (27.4 m) long with a longest span of 85 ft (25.9 m) and a deck 44 ft wide.

Who owns I-93 NB over Nh 49?

It is owned by the State Highway Agency.