US Bridges

US 4 over Mascoma River

Good

Grafton County, New Hampshire · 1.2 MI from Enfield T.L. · Structure no. 003601030004900

Built
1965
60 years old, rebuilt 2016
Condition
Good
inspected May 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
117 ft
2 main spans
Daily traffic
7,633
2023 count
Owner
State
State Highway Agency

About this bridge

US 4 over Mascoma River is a steel stringer/multi-beam or girder carrying US 4 over Mascoma River in Grafton County, New Hampshire. It was built in 1965 and reconstructed in 2016, so it is 60 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 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 7,633 vehicles a day, roughly 7% of them trucks, projected to reach 11,296 by 2043. The structure is 117 ft (35.7 m) long and 33 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesUS 4
CrossesMascoma River
Location1.2 MI from Enfield T.L.
RouteU.S. Route 4
CountyGrafton County
StateNew Hampshire
Coordinates43.652, -72.09296
Functional classRural Minor Arterial

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating49.1 US tons
Inventory rating36 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length117 ft (35.7 m)
Longest span56 ft (17.1 m)
Deck width33 ft (10.1 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,633 (2023)
Projected traffic11,296 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 US 4 over Mascoma River built?

It was built in 1965, making it 60 years old in 2025. It was reconstructed in 2016.

What condition is US 4 over Mascoma 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 May 2024.

How much traffic does US 4 over Mascoma River carry?

About 7,633 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is US 4 over Mascoma River?

The structure is 117 ft (35.7 m) long with a longest span of 56 ft (17.1 m) and a deck 33 ft wide.

Who owns US 4 over Mascoma River?

It is owned by the State Highway Agency.