US Bridges

I-93 SB over US 3 Nhrr

Fair

Grafton County, New Hampshire · 1.72 MI Thornton Tl · Structure no. 028402020006400

Built
1970
55 years old, rebuilt 2002
Condition
Fair
inspected April 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
168 ft
2 main spans
Daily traffic
7,483
2023 count
Owner
State
State Highway Agency

About this bridge

I-93 SB over US 3 Nhrr is a steel stringer/multi-beam or girder carrying I-93 SB over US 3 Nhrr in Grafton County, New Hampshire. It was built in 1970 and reconstructed in 2002, so it is 55 years old, younger than the New Hampshire average of 56.9 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 7,483 vehicles a day, roughly 10% of them trucks, projected to reach 11,074 by 2043. The structure is 168 ft (51.2 m) long and 48 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesI-93 SB
CrossesUS 3 Nhrr
Location1.72 MI Thornton Tl
RouteInterstate 93
Coordinates43.95887, -71.68033
Functional classRural Principal Arterial - Interstate

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
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 geometry2: Basically intolerable, requiring high priority of replacement
Approach roadway alignment8: Equal to present desirable criteria
Operating rating56.2 US tons
Inventory rating33.7 US tons

Structure

MaterialSteel
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20 + Mod
Structure length168 ft (51.2 m)
Longest span128 ft (39 m)
Deck width48 ft (14.5 m)
Roadway width44 ft (13.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,483 (2023)
Projected traffic11,074 by 2043
Trucks10%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway and railroad
Detour if closed1.2 mi (2 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 SB over US 3 Nhrr built?

It was built in 1970, making it 55 years old in 2025. It was reconstructed in 2002.

What condition is I-93 SB over US 3 Nhrr in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in April 2023.

How much traffic does I-93 SB over US 3 Nhrr carry?

About 7,483 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is I-93 SB over US 3 Nhrr?

The structure is 168 ft (51.2 m) long with a longest span of 128 ft (39 m) and a deck 48 ft wide.

Who owns I-93 SB over US 3 Nhrr?

It is owned by the State Highway Agency.