US Bridges

Grey Rocks Road over Nhrr

Good

Belknap County, New Hampshire · 0.3 MI from Tilton Tl · Structure no. 002000520011100

Built
2000
25 years old
Condition
Good
inspected May 2024
Type
Other
Steel
Length
95 ft
1 main span
Daily traffic
510
2023 count
Owner
State
State Highway Agency

About this bridge

Grey Rocks Road over Nhrr is a steel other carrying Grey Rocks Road over Nhrr in Belknap County, New Hampshire. It was built in 2000, so it is 25 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 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 510 vehicles a day, roughly 4% of them trucks, projected to reach 754 by 2043. The structure is 95 ft (29 m) long and 24 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesGrey Rocks Road
CrossesNhrr
Location0.3 MI from Tilton Tl
Coordinates43.47543, -71.53144
Functional classUrban Local

Condition and inspection

Good

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

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation8: Equal to present desirable criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment7: Better than present minimum criteria
Operating rating63.1 US tons
Inventory rating46 US tons

Structure

Structure typeOther
MaterialSteel
DeckClosed grating
Main spans1
Design loadHS 25 or greater
Structure length95 ft (29 m)
Longest span90 ft (27.4 m)
Deck width24 ft (7.3 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic510 (2023)
Projected traffic754 by 2043
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesRailroad
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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)
NavigationNot applicable (no waterway)

Frequently asked questions

When was Grey Rocks Road over Nhrr built?

It was built in 2000, making it 25 years old in 2025.

What condition is Grey Rocks Road over Nhrr 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 May 2024.

How much traffic does Grey Rocks Road over Nhrr carry?

About 510 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is Grey Rocks Road over Nhrr?

The structure is 95 ft (29 m) long with a longest span of 90 ft (27.4 m) and a deck 24 ft wide.

Who owns Grey Rocks Road over Nhrr?

It is owned by the State Highway Agency.