US Bridges

Nh 75 over Mad River

Fair

Strafford County, New Hampshire · .34 Mi. from Jct. Nh 11 · Structure no. 008400850013200

Built
1900
125 years old, rebuilt 1992
Condition
Fair
inspected May 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
49 ft
1 main span
Daily traffic
871
2023 count
Owner
State
State Highway Agency

About this bridge

Nh 75 over Mad River is a steel stringer/multi-beam or girder carrying Nh 75 over Mad River in Strafford County, New Hampshire. It was built in 1900 and reconstructed in 1992, so it is 125 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 871 vehicles a day, roughly 4% of them trucks, projected to reach 1,289 by 2043. The structure is 49 ft (14.9 m) long and 31 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesNh 75
CrossesMad River
Location.34 Mi. from Jct. Nh 11
RouteState Highway 0
CountyStrafford County
StateNew Hampshire
Coordinates43.38781, -71.07278
Functional classRural Minor Collector

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.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating90.9 US tons
Inventory rating54.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 25 or greater
Structure length49 ft (14.9 m)
Longest span45 ft (13.7 m)
Deck width31 ft (9.3 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic871 (2023)
Projected traffic1,289 by 2043
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.2 mi (2 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 Nh 75 over Mad River built?

It was built in 1900, making it 125 years old in 2025. It was reconstructed in 1992.

What condition is Nh 75 over Mad 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 May 2024.

How much traffic does Nh 75 over Mad River carry?

About 871 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is Nh 75 over Mad River?

The structure is 49 ft (14.9 m) long with a longest span of 45 ft (13.7 m) and a deck 31 ft wide.

Who owns Nh 75 over Mad River?

It is owned by the State Highway Agency.