US Bridges

Nh 1B over South Mill Pond

Good

Rockingham County, New Hampshire · .6 MI from JCT US 1 · Structure no. 021702350006900

Built
1985
40 years old
Condition
Good
inspected October 2023
Type
Frame
Concrete
Length
26 ft
1 main span
Daily traffic
4,588
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

Nh 1B over South Mill Pond is a concrete frame carrying Nh 1B over South Mill Pond in Rockingham County, New Hampshire. It was built in 1985, so it is 40 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 4,588 vehicles a day, roughly 3% of them trucks, projected to reach 6,790 by 2043. The structure is 26 ft (7.9 m) long and 60 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesNh 1B
CrossesSouth Mill Pond
Location.6 MI from JCT US 1
RouteState Highway 1B
CountyRockingham County
StateNew Hampshire
Coordinates43.07276, -70.75052
Functional classUrban 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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating33 US tons
Inventory rating22 US tons

Structure

Structure typeFrame
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length26 ft (7.9 m)
Longest span22 ft (6.7 m)
Deck width60 ft (18.4 m)
Roadway width48 ft (14.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,588 (2023)
Projected traffic6,790 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusNot eligible for the National Register of Historic Places
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 1B over South Mill Pond built?

It was built in 1985, making it 40 years old in 2025.

What condition is Nh 1B over South Mill Pond 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 October 2023.

How much traffic does Nh 1B over South Mill Pond carry?

About 4,588 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is Nh 1B over South Mill Pond?

The structure is 26 ft (7.9 m) long with a longest span of 22 ft (6.7 m) and a deck 60 ft wide.

Who owns Nh 1B over South Mill Pond?

It is owned by the City or Municipal Highway Agency.