US Bridges

US302 Nh 10 over Ammonoosuc River

Fair

Grafton County, New Hampshire · 2.9 MI Landaff Tl · Structure no. 015000940011400

Built
1980
45 years old, rebuilt 2009
Condition
Fair
inspected June 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
304 ft
3 main spans
Daily traffic
4,777
2023 count
Owner
State
State Highway Agency

About this bridge

US302 Nh 10 over Ammonoosuc River is a steel continuous stringer/multi-beam or girder carrying US302 Nh 10 over Ammonoosuc River in Grafton County, New Hampshire. It was built in 1980 and reconstructed in 2009, 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 4,777 vehicles a day, roughly 7% of them trucks, projected to reach 7,069 by 2043. The structure is 304 ft (92.7 m) long and 47 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesUS302 Nh 10
CrossesAmmonoosuc River
Location2.9 MI Landaff Tl
RouteU.S. Route 302
CountyGrafton County
StateNew Hampshire
Coordinates44.23797, -71.88016
Functional classRural 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
Deck8 Very GoodNo problems noted.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating27.7 US tons
Inventory rating16.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length304 ft (92.7 m)
Longest span114 ft (34.7 m)
Deck width47 ft (14.2 m)
Roadway width43 ft (13 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,777 (2023)
Projected traffic7,069 by 2043
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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 US302 Nh 10 over Ammonoosuc River built?

It was built in 1980, making it 45 years old in 2025. It was reconstructed in 2009.

What condition is US302 Nh 10 over Ammonoosuc River 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 June 2024.

How much traffic does US302 Nh 10 over Ammonoosuc River carry?

About 4,777 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is US302 Nh 10 over Ammonoosuc River?

The structure is 304 ft (92.7 m) long with a longest span of 114 ft (34.7 m) and a deck 47 ft wide.

Who owns US302 Nh 10 over Ammonoosuc River?

It is owned by the State Highway Agency.