US Bridges

Riverside Drive over Mascoma River

FairPosted for load

Grafton County, New Hampshire · 1.0MI JCT Us. 4 · Structure no. 014401540011300

Built
1991
34 years old
Condition
Fair
inspected July 2024
Type
Truss - Thru
Wood or Timber
Length
76 ft
1 main span
Daily traffic
1,736
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

Riverside Drive over Mascoma River is a wood or timber truss - thru carrying Riverside Drive over Mascoma River in Grafton County, New Hampshire. It was built in 1991, so it is 34 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 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. Its operating status is: posted for load restriction.

It carries about 1,736 vehicles a day, roughly 3% of them trucks, projected to reach 2,569 by 2043. The structure is 76 ft (23.2 m) long and 15 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesRiverside Drive
CrossesMascoma River
Location1.0MI JCT Us. 4
RouteCity Street 0
CountyGrafton County
StateNew Hampshire
Coordinates43.63874, -72.22244
Functional classUrban 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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation2: Basically intolerable, requiring high priority of replacement
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating18 US tons
Inventory rating10.8 US tons

Structure

Structure typeTruss - Thru
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadUnknown
Structure length76 ft (23.2 m)
Longest span53 ft (16.2 m)
Deck width15 ft (4.5 m)
Roadway width15 ft (4.5 m)
Vertical clearance over deck13 ft (3.9 m)

Traffic and service

Average daily traffic1,736 (2023)
Projected traffic2,569 by 2043
Trucks3%
Lanes on structure1
Traffic directionOne-lane bridge for two-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 Riverside Drive over Mascoma River built?

It was built in 1991, making it 34 years old in 2025.

What condition is Riverside Drive over Mascoma River 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 July 2024.

How much traffic does Riverside Drive over Mascoma River carry?

About 1,736 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is Riverside Drive over Mascoma River?

The structure is 76 ft (23.2 m) long with a longest span of 53 ft (16.2 m) and a deck 15 ft wide.

Who owns Riverside Drive over Mascoma River?

It is owned by the City or Municipal Highway Agency.