US Bridges

I-93 SB over Harvard Brook

Good

Grafton County, New Hampshire · 2.1 Mi.No.Woodstock T/L · Structure no. 014801960009200

Built
1985
40 years old
Condition
Good
inspected May 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
123 ft
1 main span
Daily traffic
5,796
2023 count
Owner
State
State Highway Agency

About this bridge

I-93 SB over Harvard Brook is a steel stringer/multi-beam or girder carrying I-93 SB over Harvard Brook in Grafton County, New Hampshire. It was built in 1985, so it is 40 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 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 5,796 vehicles a day, roughly 9% of them trucks, projected to reach 8,578 by 2043. The structure is 123 ft (37.5 m) long and 78 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

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CarriesI-93 SB
CrossesHarvard Brook
Location2.1 Mi.No.Woodstock T/L
RouteInterstate 93
CountyGrafton County
StateNew Hampshire
Coordinates44.06392, -71.6899
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.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating90.5 US tons
Inventory rating54.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20 + Mod
Structure length123 ft (37.5 m)
Longest span118 ft (36 m)
Deck width78 ft (23.9 m)
Roadway width72 ft (21.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5,796 (2023)
Projected traffic8,578 by 2043
Trucks9%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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)
NavigationNo navigation control on waterway

Frequently asked questions

When was I-93 SB over Harvard Brook built?

It was built in 1985, making it 40 years old in 2025.

What condition is I-93 SB over Harvard Brook 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 May 2023.

How much traffic does I-93 SB over Harvard Brook carry?

About 5,796 vehicles per day (2023 count), of which roughly 9% are trucks.

How long is I-93 SB over Harvard Brook?

The structure is 123 ft (37.5 m) long with a longest span of 118 ft (36 m) and a deck 78 ft wide.

Who owns I-93 SB over Harvard Brook?

It is owned by the State Highway Agency.