US Bridges

Center Hill Road over Blakes Brook

Good

Merrimack County, New Hampshire · 0.3MI NH9 · Structure no. 007901180011600

Built
2008
17 years old
Condition
Good
inspected August 2024
Type
Culvert
Concrete
Length
36 ft
1 main span
Daily traffic
852
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

Center Hill Road over Blakes Brook is a concrete culvert carrying Center Hill Road over Blakes Brook in Merrimack County, New Hampshire. It was built in 2008, so it is 17 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 852 vehicles a day, roughly 4% of them trucks, projected to reach 1,260 by 2043. The structure is 36 ft (11 m) long. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesCenter Hill Road
CrossesBlakes Brook
Location0.3MI NH9
CountyMerrimack County
StateNew Hampshire
Coordinates43.21921, -71.32647
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
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert7 GoodSome minor problems.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating77.2 US tons
Inventory rating46.3 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 25 or greater
Structure length36 ft (11 m)
Longest span34 ft (10.3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic852 (2023)
Projected traffic1,260 by 2043
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 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 Center Hill Road over Blakes Brook built?

It was built in 2008, making it 17 years old in 2025.

What condition is Center Hill Road over Blakes 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 August 2024.

How much traffic does Center Hill Road over Blakes Brook carry?

About 852 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is Center Hill Road over Blakes Brook?

The structure is 36 ft (11 m) long with a longest span of 34 ft (10.3 m).

Who owns Center Hill Road over Blakes Brook?

It is owned by the City or Municipal Highway Agency.