US Bridges

Bunker Hill Road over Mill Brook

Good

Carroll County, New Hampshire · 2.1 Mi. RTE.113 · Structure no. 025201100007200

Built
2020
5 years old
Condition
Good
inspected October 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
43 ft
1 main span
Daily traffic
96
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

Bunker Hill Road over Mill Brook is a steel stringer/multi-beam or girder carrying Bunker Hill Road over Mill Brook in Carroll County, New Hampshire. It was built in 2020, so it is 5 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 9 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 96 vehicles a day, roughly 4% of them trucks, projected to reach 142 by 2043. The structure is 43 ft (13.1 m) long and 18 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

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CarriesBunker Hill Road
CrossesMill Brook
Location2.1 Mi. RTE.113
CountyCarroll County
StateNew Hampshire
Coordinates43.85553, -71.30787
Functional classRural Local

Condition and inspection

Good

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

ComponentRatingMeaning
Deck9 ExcellentNo problems noted.
Superstructure9 ExcellentNo problems noted.
Substructure9 ExcellentNo problems noted.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
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 geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating32.2 US tons
Inventory rating21.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckWood or timber
Main spans1
Design loadUnknown
Structure length43 ft (13.1 m)
Longest span37 ft (11.4 m)
Deck width18 ft (5.5 m)
Roadway width18 ft (5.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic96 (2023)
Projected traffic142 by 2043
Trucks4%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 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 Bunker Hill Road over Mill Brook built?

It was built in 2020, making it 5 years old in 2025.

What condition is Bunker Hill Road over Mill Brook 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 Bunker Hill Road over Mill Brook carry?

About 96 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is Bunker Hill Road over Mill Brook?

The structure is 43 ft (13.1 m) long with a longest span of 37 ft (11.4 m) and a deck 18 ft wide.

Who owns Bunker Hill Road over Mill Brook?

It is owned by the City or Municipal Highway Agency.