US Bridges

HWY Granite Ave over Water Neponset River

FairPosted for load

Suffolk County, Massachusetts · Milton Town Line · Structure no. B160223A3DOTNBI

Built
1959
66 years old
Condition
Fair
inspected May 2023
Type
Movable - Bascule
Steel
Length
187 ft
1 main span
Daily traffic
39,339
2020 count
Owner
State
State Highway Agency

About this bridge

HWY Granite Ave over Water Neponset River is a steel movable - bascule carrying HWY Granite Ave over Water Neponset River in Suffolk County, Massachusetts. It was built in 1959, so it is 66 years old, older 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 5 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 39,339 vehicles a day, roughly 6% of them trucks, projected to reach 56,855 by 2032. The structure is 187 ft (57 m) long and 51 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesHWY Granite Ave
CrossesWater Neponset River
LocationMilton Town Line
CountySuffolk County
StateMassachusetts
Coordinates42.27748, -71.0533
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating16.2 US tons
Inventory rating9.7 US tons

Structure

Structure typeMovable - Bascule
MaterialSteel
DeckConcrete, cast-in-place
Main spans1 (+3 approach)
Design loadH 20
Structure length187 ft (57 m)
Longest span65 ft (19.8 m)
Deck width51 ft (15.5 m)
Roadway width48 ft (14.6 m)
Vertical clearance over deck14 ft (4.3 m)

Traffic and service

Average daily traffic39,339 (2020)
Projected traffic56,855 by 2032
Trucks6%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$8.8 million (2025 estimate)
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was HWY Granite Ave over Water Neponset River built?

It was built in 1959, making it 66 years old in 2025.

What condition is HWY Granite Ave over Water Neponset 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 May 2023.

How much traffic does HWY Granite Ave over Water Neponset River carry?

About 39,339 vehicles per day (2020 count), of which roughly 6% are trucks.

How long is HWY Granite Ave over Water Neponset River?

The structure is 187 ft (57 m) long with a longest span of 65 ft (19.8 m) and a deck 51 ft wide.

Who owns HWY Granite Ave over Water Neponset River?

It is owned by the State Highway Agency.