US Bridges

Nh 77 over Canal 2 Choate Bk

Fair

Hillsborough County, New Hampshire · 1.0 MI W Dunbarton T.L. · Structure no. 026701590017800

Built
1960
65 years old
Condition
Fair
inspected June 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
453 ft
3 main spans
Daily traffic
4,701
2023 count
Owner
State
State Highway Agency

About this bridge

Nh 77 over Canal 2 Choate Bk is a steel stringer/multi-beam or girder carrying Nh 77 over Canal 2 Choate Bk in Hillsborough County, New Hampshire. It was built in 1960, so it is 65 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 5 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 4,701 vehicles a day, roughly 4% of them trucks, projected to reach 6,957 by 2043. The structure is 453 ft (138.1 m) long and 32 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

Open in Google Maps
CarriesNh 77
CrossesCanal 2 Choate Bk
Location1.0 MI W Dunbarton T.L.
RouteState Highway 77
CountyHillsborough County
StateNew Hampshire
Coordinates43.13849, -71.68034
Functional classRural Major 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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating49.7 US tons
Inventory rating32.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length453 ft (138.1 m)
Longest span182 ft (55.5 m)
Deck width32 ft (9.8 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,701 (2023)
Projected traffic6,957 by 2043
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.8 mi (11 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 Nh 77 over Canal 2 Choate Bk built?

It was built in 1960, making it 65 years old in 2025.

What condition is Nh 77 over Canal 2 Choate Bk 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 2023.

How much traffic does Nh 77 over Canal 2 Choate Bk carry?

About 4,701 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is Nh 77 over Canal 2 Choate Bk?

The structure is 453 ft (138.1 m) long with a longest span of 182 ft (55.5 m) and a deck 32 ft wide.

Who owns Nh 77 over Canal 2 Choate Bk?

It is owned by the State Highway Agency.