US Bridges

ST 3 A/Main ST over Water North River

Fair

Plymouth County, Massachusetts · At Marshfield Scituate Tl · Structure no. M07002AMBDOTNBI

Built
2001
24 years old
Condition
Fair
inspected April 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
554 ft
4 main spans
Daily traffic
18,557
2023 count
Owner
State
State Highway Agency

About this bridge

ST 3 A/Main ST over Water North River is a steel continuous stringer/multi-beam or girder carrying ST 3 A/Main ST over Water North River in Plymouth County, Massachusetts. It was built in 2001, so it is 24 years old, younger than the Massachusetts average of 63.8 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.

It carries about 18,557 vehicles a day, roughly 2% of them trucks, projected to reach 28,427 by 2031. The structure is 554 ft (169 m) long and 53 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

Location

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CarriesST 3 A/Main ST
CrossesWater North River
LocationAt Marshfield Scituate Tl
RouteState Highway 3A
CountyPlymouth County
StateMassachusetts
Coordinates42.16111, -70.74236
Functional classUrban Other Principal Arterial

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.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating72.2 US tons
Inventory rating44 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length554 ft (169 m)
Longest span166 ft (50.6 m)
Deck width53 ft (16.2 m)
Roadway width44 ft (13.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic18,557 (2023)
Projected traffic28,427 by 2031
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesRelief for waterway
Detour if closed9.9 mi (16 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedOther structural work, including hydraulic replacements
Estimated improvement cost$5.4 million (2025 estimate)
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was ST 3 A/Main ST over Water North River built?

It was built in 2001, making it 24 years old in 2025.

What condition is ST 3 A/Main ST over Water North 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 April 2024.

How much traffic does ST 3 A/Main ST over Water North River carry?

About 18,557 vehicles per day (2023 count), of which roughly 2% are trucks.

How long is ST 3 A/Main ST over Water North River?

The structure is 554 ft (169 m) long with a longest span of 166 ft (50.6 m) and a deck 53 ft wide.

Who owns ST 3 A/Main ST over Water North River?

It is owned by the State Highway Agency.