US Bridges

NH101 over Souhegan River

Good

Hillsborough County, New Hampshire · 0.04 MI Milford Tl · Structure no. 000701880009700

Built
1971
54 years old
Condition
Good
inspected June 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
240 ft
2 main spans
Daily traffic
15,196
2023 count
Owner
State
State Highway Agency

About this bridge

NH101 over Souhegan River is a steel continuous stringer/multi-beam or girder carrying NH101 over Souhegan River in Hillsborough County, New Hampshire. It was built in 1971, so it is 54 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 good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 15,196 vehicles a day, roughly 7% of them trucks, projected to reach 22,490 by 2043. The structure is 240 ft (73.2 m) long and 48 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesNH101
CrossesSouhegan River
Location0.04 MI Milford Tl
RouteState Highway 101
CountyHillsborough County
StateNew Hampshire
Coordinates42.82698, -71.61706
Functional classUrban Other Principal Arterial

Condition and inspection

Good

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than 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 rating52.2 US tons
Inventory rating34.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20 + Mod
Structure length240 ft (73.2 m)
Longest span119 ft (36.3 m)
Deck width48 ft (14.5 m)
Roadway width44 ft (13.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic15,196 (2023)
Projected traffic22,490 by 2043
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemYes

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 NH101 over Souhegan River built?

It was built in 1971, making it 54 years old in 2025.

What condition is NH101 over Souhegan 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 June 2023.

How much traffic does NH101 over Souhegan River carry?

About 15,196 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is NH101 over Souhegan River?

The structure is 240 ft (73.2 m) long with a longest span of 119 ft (36.3 m) and a deck 48 ft wide.

Who owns NH101 over Souhegan River?

It is owned by the State Highway Agency.