US Bridges

I 495 over Water Nemasket River

Fair

Plymouth County, Massachusetts · 1 M S of RTE 495 / 105 · Structure no. M18051462DOTNBI

Built
1958
67 years old
Condition
Fair
inspected September 2024
Type
Tee Beam
Concrete
Length
43 ft
1 main span
Daily traffic
44,600
2023 count
Owner
State
State Highway Agency

About this bridge

I 495 over Water Nemasket River is a concrete tee beam carrying I 495 over Water Nemasket River in Plymouth County, Massachusetts. It was built in 1958, so it is 67 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 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 44,600 vehicles a day, roughly 6% of them trucks, projected to reach 102,654 by 2031. The structure is 43 ft (13.1 m) long and 128 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

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CarriesI 495
CrossesWater Nemasket River
Location1 M S of RTE 495 / 105
RouteInterstate 495
CountyPlymouth County
StateMassachusetts
Coordinates41.87852, -70.91141
Functional classUrban Principal Arterial - Interstate

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionSeptember 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 rating46.6 US tons
Inventory rating27.8 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 20
Structure length43 ft (13.1 m)
Longest span39 ft (11.9 m)
Deck width128 ft (39 m)
Roadway width122 ft (37.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic44,600 (2023)
Projected traffic102,654 by 2031
Trucks6%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.8 mi (11 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$5.3 million (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was I 495 over Water Nemasket River built?

It was built in 1958, making it 67 years old in 2025.

What condition is I 495 over Water Nemasket 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 September 2024.

How much traffic does I 495 over Water Nemasket River carry?

About 44,600 vehicles per day (2023 count), of which roughly 6% are trucks.

How long is I 495 over Water Nemasket River?

The structure is 43 ft (13.1 m) long with a longest span of 39 ft (11.9 m) and a deck 128 ft wide.

Who owns I 495 over Water Nemasket River?

It is owned by the State Highway Agency.