US Bridges

Nh 16 SP Tpk over Blackwater Road

Fair

Strafford County, New Hampshire · .6 MI from Dover T.L. · Structure no. 022201940014900

Built
1957
68 years old
Condition
Fair
inspected July 2023
Type
Frame
Concrete
Length
35 ft
1 main span
Daily traffic
30,695
2023 count
Owner
Toll Authority
State Toll Authority

About this bridge

Nh 16 SP Tpk over Blackwater Road is a concrete frame carrying Nh 16 SP Tpk over Blackwater Road in Strafford County, New Hampshire. It was built in 1957, 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 5 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 30,695 vehicles a day, roughly 8% of them trucks, projected to reach 45,428 by 2043. The structure is 35 ft (10.7 m) long and 95 ft wide. If it were closed, the detour would be 8.7 mi (14 km).

Location

Open in Google Maps
CarriesNh 16 SP Tpk
CrossesBlackwater Road
Location.6 MI from Dover T.L.
RouteState Highway 16
CountyStrafford County
StateNew Hampshire
Coordinates43.25623, -70.94237
Functional classUrban Principal Arterial - Other Freeway or Expressway

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating110.1 US tons
Inventory rating83.3 US tons

Structure

Structure typeFrame
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length35 ft (10.7 m)
Longest span31 ft (9.4 m)
Deck width95 ft (28.9 m)
Roadway width87 ft (26.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic30,695 (2023)
Projected traffic45,428 by 2043
Trucks8%
Lanes on structure4
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed8.7 mi (14 km)
TollOn a toll road
National Highway SystemYes
Strategic Highway NetworkInterstate 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 16 SP Tpk over Blackwater Road built?

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

What condition is Nh 16 SP Tpk over Blackwater Road 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 July 2023.

How much traffic does Nh 16 SP Tpk over Blackwater Road carry?

About 30,695 vehicles per day (2023 count), of which roughly 8% are trucks.

How long is Nh 16 SP Tpk over Blackwater Road?

The structure is 35 ft (10.7 m) long with a longest span of 31 ft (9.4 m) and a deck 95 ft wide.

Who owns Nh 16 SP Tpk over Blackwater Road?

It is owned by the State Toll Authority.