US Bridges

I-93 NB over Blair Road

Good

Grafton County, New Hampshire · 2.1 MI from Plymouth T.L. · Structure no. 003501130007800

Built
1963
62 years old, rebuilt 2004
Condition
Good
inspected April 2023
Type
Frame
Concrete
Length
58 ft
1 main span
Daily traffic
10,585
2023 count
Owner
State
State Highway Agency

About this bridge

I-93 NB over Blair Road is a concrete frame carrying I-93 NB over Blair Road in Grafton County, New Hampshire. It was built in 1963 and reconstructed in 2004, so it is 62 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 10,585 vehicles a day, roughly 9% of them trucks, projected to reach 15,665 by 2043. The structure is 58 ft (17.7 m) long and 51 ft wide.

Location

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CarriesI-93 NB
CrossesBlair Road
Location2.1 MI from Plymouth T.L.
RouteInterstate 93
CountyGrafton County
StateNew Hampshire
Coordinates43.81145, -71.67013
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.
Superstructure7 GoodSome minor problems.
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 geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating95 US tons
Inventory rating57 US tons

Structure

Structure typeFrame
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20 + Mod
Structure length58 ft (17.7 m)
Longest span50 ft (15.2 m)
Deck width51 ft (15.5 m)
Roadway width46 ft (13.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic10,585 (2023)
Projected traffic15,665 by 2043
Trucks9%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed—
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 Blair Road built?

It was built in 1963, making it 62 years old in 2025. It was reconstructed in 2004.

What condition is I-93 NB over Blair Road 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 Blair Road carry?

About 10,585 vehicles per day (2023 count), of which roughly 9% are trucks.

How long is I-93 NB over Blair Road?

The structure is 58 ft (17.7 m) long with a longest span of 50 ft (15.2 m) and a deck 51 ft wide.

Who owns I-93 NB over Blair Road?

It is owned by the State Highway Agency.