US Bridges

String Bridge ST over Squamscott River

Good

Rockingham County, New Hampshire · 0.05MI RTE 108 · Structure no. 008201030007400

Built
1935
90 years old, rebuilt 2018
Condition
Good
inspected August 2024
Type
Frame
Concrete
Length
58 ft
1 main span
Daily traffic
1,568
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

String Bridge ST over Squamscott River is a concrete frame carrying String Bridge ST over Squamscott River in Rockingham County, New Hampshire. It was built in 1935 and reconstructed in 2018, so it is 90 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 1,568 vehicles a day, roughly 4% of them trucks, projected to reach 2,320 by 2043. The structure is 58 ft (17.7 m) long and 30 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesString Bridge ST
CrossesSquamscott River
Location0.05MI RTE 108
RouteCity Street 0
Coordinates42.98207, -70.94531
Functional classUrban Local

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 inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating36.2 US tons
Inventory rating21.6 US tons

Structure

Structure typeFrame
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 10
Structure length58 ft (17.7 m)
Longest span50 ft (15.2 m)
Deck width30 ft (9 m)
Roadway width21 ft (6.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,568 (2023)
Projected traffic2,320 by 2043
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal 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 String Bridge ST over Squamscott River built?

It was built in 1935, making it 90 years old in 2025. It was reconstructed in 2018.

What condition is String Bridge ST over Squamscott River 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 August 2024.

How much traffic does String Bridge ST over Squamscott River carry?

About 1,568 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is String Bridge ST over Squamscott River?

The structure is 58 ft (17.7 m) long with a longest span of 50 ft (15.2 m) and a deck 30 ft wide.

Who owns String Bridge ST over Squamscott River?

It is owned by the City or Municipal Highway Agency.