US Bridges

I-93 NB over Merrimack River CSX RD

Fair

Hillsborough County, New Hampshire · At Manchester-Hooksett Tl · Structure no. 016100590008700

Built
1976
49 years old, rebuilt 2013
Condition
Fair
inspected April 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
826 ft
4 main spans
Daily traffic
48,395
2023 count
Owner
State
State Highway Agency

About this bridge

I-93 NB over Merrimack River CSX RD is a steel continuous stringer/multi-beam or girder carrying I-93 NB over Merrimack River CSX RD in Hillsborough County, New Hampshire. It was built in 1976 and reconstructed in 2013, so it is 49 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 48,395 vehicles a day, roughly 6% of them trucks, projected to reach 71,624 by 2043. The structure is 826 ft (251.8 m) long and 69 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI-93 NB
CrossesMerrimack River CSX RD
LocationAt Manchester-Hooksett Tl
RouteInterstate 93
CountyHillsborough County
StateNew Hampshire
Coordinates43.04094, -71.46058
Functional classUrban 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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating54 US tons
Inventory rating36 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20 + Mod
Structure length826 ft (251.8 m)
Longest span228 ft (69.5 m)
Deck width69 ft (20.9 m)
Roadway width65 ft (19.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic48,395 (2023)
Projected traffic71,624 by 2043
Trucks6%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway, waterway 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 NB over Merrimack River CSX RD built?

It was built in 1976, making it 49 years old in 2025. It was reconstructed in 2013.

What condition is I-93 NB over Merrimack River CSX RD 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 NB over Merrimack River CSX RD carry?

About 48,395 vehicles per day (2023 count), of which roughly 6% are trucks.

How long is I-93 NB over Merrimack River CSX RD?

The structure is 826 ft (251.8 m) long with a longest span of 228 ft (69.5 m) and a deck 69 ft wide.

Who owns I-93 NB over Merrimack River CSX RD?

It is owned by the State Highway Agency.