US Bridges

Main Street over Contoocook River

Good

Hillsborough County, New Hampshire · 85 Ft FR Granite ST · Structure no. 020800920008900

Built
1940
85 years old, rebuilt 2022
Condition
Good
inspected July 2023
Type
Frame
Concrete
Length
86 ft
1 main span
Daily traffic
6,119
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

Main Street over Contoocook River is a concrete frame carrying Main Street over Contoocook River in Hillsborough County, New Hampshire. It was built in 1940 and reconstructed in 2022, so it is 85 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 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 6,119 vehicles a day, roughly 4% of them trucks, projected to reach 9,056 by 2043. The structure is 86 ft (26.2 m) long and 48 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

CarriesMain Street
CrossesContoocook River
Location85 Ft FR Granite ST
Coordinates42.87744, -71.94835
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 protection7 GoodSome minor problems.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation9: Superior to present desirable criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating110.1 US tons
Inventory rating80.8 US tons

Structure

Structure typeFrame
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHL 93
Structure length86 ft (26.2 m)
Longest span75 ft (22.9 m)
Deck width48 ft (14.6 m)
Roadway width34 ft (10.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,119 (2023)
Projected traffic9,056 by 2043
Trucks4%
Lanes on structure3
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusEligible 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 Main Street over Contoocook River built?

It was built in 1940, making it 85 years old in 2025. It was reconstructed in 2022.

What condition is Main Street over Contoocook River 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 July 2023.

How much traffic does Main Street over Contoocook River carry?

About 6,119 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is Main Street over Contoocook River?

The structure is 86 ft (26.2 m) long with a longest span of 75 ft (22.9 m) and a deck 48 ft wide.

Who owns Main Street over Contoocook River?

It is owned by the City or Municipal Highway Agency.