US Bridges

Riverdale Road over Piscataquog River

Good

Hillsborough County, New Hampshire · 320 Ft FR New Boston Tl · Structure no. 026701650002400

Built
1940
85 years old, rebuilt 1996
Condition
Good
inspected August 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
65 ft
1 main span
Daily traffic
641
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

Riverdale Road over Piscataquog River is a steel stringer/multi-beam or girder carrying Riverdale Road over Piscataquog River in Hillsborough County, New Hampshire. It was built in 1940 and reconstructed in 1996, 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 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 641 vehicles a day, roughly 4% of them trucks, projected to reach 948 by 2043. The structure is 65 ft (19.8 m) long and 32 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesRiverdale Road
CrossesPiscataquog River
Location320 Ft FR New Boston Tl
CountyHillsborough County
StateNew Hampshire
Coordinates43.03256, -71.64617
Functional classRural Minor Collector

Condition and inspection

Good

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating56 US tons
Inventory rating41 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 25 or greater
Structure length65 ft (19.8 m)
Longest span60 ft (18.3 m)
Deck width32 ft (9.8 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic641 (2023)
Projected traffic948 by 2043
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal 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 Riverdale Road over Piscataquog River built?

It was built in 1940, making it 85 years old in 2025. It was reconstructed in 1996.

What condition is Riverdale Road over Piscataquog 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 August 2023.

How much traffic does Riverdale Road over Piscataquog River carry?

About 641 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is Riverdale Road over Piscataquog River?

The structure is 65 ft (19.8 m) long with a longest span of 60 ft (18.3 m) and a deck 32 ft wide.

Who owns Riverdale Road over Piscataquog River?

It is owned by the City or Municipal Highway Agency.