US Bridges

Base Station Road over Black Brook

Fair

Coos County, New Hampshire · 2.98 MI NE JCT RTE US 302 · Structure no. 005550670017900

Built
1934
91 years old, rebuilt 1969
Condition
Fair
inspected June 2024
Type
Culvert
Concrete
Length
24 ft
1 main span
Daily traffic
1,793
2023 count
Owner
State
State Highway Agency

About this bridge

Base Station Road over Black Brook is a concrete culvert carrying Base Station Road over Black Brook in Coos County, New Hampshire. It was built in 1934 and reconstructed in 1969, so it is 91 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 1,793 vehicles a day, roughly 10% of them trucks, projected to reach 2,653 by 2043. The structure is 24 ft (7.3 m) long. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesBase Station Road
CrossesBlack Brook
Location2.98 MI NE JCT RTE US 302
RouteState Highway 0
CountyCoos County
StateNew Hampshire
Coordinates44.2656, -71.40769
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
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating45.7 US tons
Inventory rating27.4 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans1
Design loadUnknown
Structure length24 ft (7.3 m)
Longest span24 ft (7.3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,793 (2023)
Projected traffic2,653 by 2043
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 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 Base Station Road over Black Brook built?

It was built in 1934, making it 91 years old in 2025. It was reconstructed in 1969.

What condition is Base Station Road over Black Brook 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 June 2024.

How much traffic does Base Station Road over Black Brook carry?

About 1,793 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is Base Station Road over Black Brook?

The structure is 24 ft (7.3 m) long with a longest span of 24 ft (7.3 m).

Who owns Base Station Road over Black Brook?

It is owned by the State Highway Agency.