US Bridges

Nh 16 SP Tpk over Lyman Brook

Fair

Strafford County, New Hampshire · 1.8 MI N of Rochester Tl · Structure no. 017302190011200

Built
1980
45 years old
Condition
Fair
inspected July 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
312 ft
3 main spans
Daily traffic
16,645
2023 count
Owner
Toll Authority
State Toll Authority

About this bridge

Nh 16 SP Tpk over Lyman Brook is a steel continuous stringer/multi-beam or girder carrying Nh 16 SP Tpk over Lyman Brook in Strafford County, New Hampshire. It was built in 1980, so it is 45 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 16,645 vehicles a day, roughly 7% of them trucks, projected to reach 24,634 by 2043. The structure is 312 ft (95.1 m) long and 52 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

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CarriesNh 16 SP Tpk
CrossesLyman Brook
Location1.8 MI N of Rochester Tl
RouteState Highway 16
CountyStrafford County
StateNew Hampshire
Coordinates43.39811, -71.00356
Functional classRural Principal Arterial - Other

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating56.1 US tons
Inventory rating33.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length312 ft (95.1 m)
Longest span120 ft (36.6 m)
Deck width52 ft (15.8 m)
Roadway width43 ft (13 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic16,645 (2023)
Projected traffic24,634 by 2043
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 km)
TollOn a free road
National Highway SystemYes

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)
NavigationNo navigation control on waterway

Frequently asked questions

When was Nh 16 SP Tpk over Lyman Brook built?

It was built in 1980, making it 45 years old in 2025.

What condition is Nh 16 SP Tpk over Lyman Brook 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 2024.

How much traffic does Nh 16 SP Tpk over Lyman Brook carry?

About 16,645 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is Nh 16 SP Tpk over Lyman Brook?

The structure is 312 ft (95.1 m) long with a longest span of 120 ft (36.6 m) and a deck 52 ft wide.

Who owns Nh 16 SP Tpk over Lyman Brook?

It is owned by the State Toll Authority.