US Bridges

Nh 1B over Piscataqua Estuary

Fair

Rockingham County, New Hampshire · 1.3 MI from JCT Rt 1 · Structure no. 021702410005300

Built
1955
70 years old, rebuilt 2020
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
544 ft
10 main spans
Daily traffic
3,041
2023 count
Owner
State
State Highway Agency

About this bridge

Nh 1B over Piscataqua Estuary is a steel continuous stringer/multi-beam or girder carrying Nh 1B over Piscataqua Estuary in Rockingham County, New Hampshire. It was built in 1955 and reconstructed in 2020, so it is 70 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 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 3,041 vehicles a day, roughly 3% of them trucks, projected to reach 4,500 by 2043. The structure is 544 ft (165.8 m) long and 34 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

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CarriesNh 1B
CrossesPiscataqua Estuary
Location1.3 MI from JCT Rt 1
RouteState Highway 1B
CountyRockingham County
StateNew Hampshire
Coordinates43.07098, -70.74301
Functional classUrban Minor Arterial

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 inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating50 US tons
Inventory rating36 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans10
Design loadHS 20
Structure length544 ft (165.8 m)
Longest span60 ft (18.3 m)
Deck width34 ft (10.5 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,041 (2023)
Projected traffic4,500 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
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 Nh 1B over Piscataqua Estuary built?

It was built in 1955, making it 70 years old in 2025. It was reconstructed in 2020.

What condition is Nh 1B over Piscataqua Estuary 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 August 2023.

How much traffic does Nh 1B over Piscataqua Estuary carry?

About 3,041 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is Nh 1B over Piscataqua Estuary?

The structure is 544 ft (165.8 m) long with a longest span of 60 ft (18.3 m) and a deck 34 ft wide.

Who owns Nh 1B over Piscataqua Estuary?

It is owned by the State Highway Agency.