US Bridges

NH101 over Merrimack Road

Good

Hillsborough County, New Hampshire · 0.7 MI Milford Tl · Structure no. 000701750009900

Built
1969
56 years old, rebuilt 2011
Condition
Good
inspected June 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
72 ft
1 main span
Daily traffic
15,196
2023 count
Owner
State
State Highway Agency

About this bridge

NH101 over Merrimack Road is a steel stringer/multi-beam or girder carrying NH101 over Merrimack Road in Hillsborough County, New Hampshire. It was built in 1969 and reconstructed in 2011, so it is 56 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 72 ft (21.9 m) long and 46 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesNH101
CrossesMerrimack Road
Location0.7 MI Milford Tl
RouteState Highway 101
CountyHillsborough County
StateNew Hampshire
Coordinates42.8366, -71.619
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.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating56.7 US tons
Inventory rating34 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length72 ft (21.9 m)
Longest span68 ft (20.7 m)
Deck width46 ft (14 m)
Roadway width43 ft (13.1 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
CrossesHighway
Detour if closed1.2 mi (2 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)
NavigationNot applicable (no waterway)

Frequently asked questions

When was NH101 over Merrimack Road built?

It was built in 1969, making it 56 years old in 2025. It was reconstructed in 2011.

What condition is NH101 over Merrimack Road 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 Merrimack Road carry?

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

How long is NH101 over Merrimack Road?

The structure is 72 ft (21.9 m) long with a longest span of 68 ft (20.7 m) and a deck 46 ft wide.

Who owns NH101 over Merrimack Road?

It is owned by the State Highway Agency.