US Bridges

Nh 9 Silver ST over Nh 16 SP Tpk

Fair

Strafford County, New Hampshire · 0.3 Mi. from JCT NH155 · Structure no. 006501210010600

Built
1957
68 years old, rebuilt 2000
Condition
Fair
inspected April 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
191 ft
4 main spans
Daily traffic
23,667
2023 count
Owner
Toll Authority
State Toll Authority

About this bridge

Nh 9 Silver ST over Nh 16 SP Tpk is a steel continuous stringer/multi-beam or girder carrying Nh 9 Silver ST over Nh 16 SP Tpk in Strafford County, New Hampshire. It was built in 1957 and reconstructed in 2000, so it is 68 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 23,667 vehicles a day, roughly 8% of them trucks, projected to reach 35,027 by 2043. The structure is 191 ft (58.2 m) long and 65 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesNh 9 Silver ST
CrossesNh 16 SP Tpk
Location0.3 Mi. from JCT NH155
RouteState Highway 4
CountyStrafford County
StateNew Hampshire
Coordinates43.1851, -70.88701
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.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating99 US tons
Inventory rating63.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, precast panels
Main spans4
Design loadHS 25 or greater
Structure length191 ft (58.2 m)
Longest span55 ft (16.8 m)
Deck width65 ft (19.7 m)
Roadway width52 ft (15.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic23,667 (2023)
Projected traffic35,027 by 2043
Trucks8%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesHighway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo
Strategic Highway NetworkNon-Interstate STRAHNET route

Ownership and planned work

OwnerState Toll Authority
Maintained byState Toll Authority
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)
NavigationNot applicable (no waterway)

Frequently asked questions

When was Nh 9 Silver ST over Nh 16 SP Tpk built?

It was built in 1957, making it 68 years old in 2025. It was reconstructed in 2000.

What condition is Nh 9 Silver ST over Nh 16 SP Tpk 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 Nh 9 Silver ST over Nh 16 SP Tpk carry?

About 23,667 vehicles per day (2023 count), of which roughly 8% are trucks.

How long is Nh 9 Silver ST over Nh 16 SP Tpk?

The structure is 191 ft (58.2 m) long with a longest span of 55 ft (16.8 m) and a deck 65 ft wide.

Who owns Nh 9 Silver ST over Nh 16 SP Tpk?

It is owned by the State Toll Authority.