US Bridges

I 495 SB over Water Assabet River

Poor

Middlesex County, Massachusetts · 0.25 MI NW Rt 290 · Structure no. H2501627GDOTNBI

Built
1963
62 years old
Condition
Poor
inspected July 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
83 ft
1 main span
Daily traffic
47,879
2023 count
Owner
State
State Highway Agency

About this bridge

I 495 SB over Water Assabet River is a steel stringer/multi-beam or girder carrying I 495 SB over Water Assabet River in Middlesex County, Massachusetts. It was built in 1963, so it is 62 years old, younger than the Massachusetts average of 63.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 47,879 vehicles a day, roughly 19% of them trucks, projected to reach 78,965 by 2032. The structure is 83 ft (25.3 m) long and 56 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

CarriesI 495 SB
CrossesWater Assabet River
Location0.25 MI NW Rt 290
RouteInterstate 495
Coordinates42.36838, -71.5953
Functional classUrban Principal Arterial - Interstate

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 2023
Inspection intervalevery 12 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating57.7 US tons
Inventory rating34.5 US tons

Structure

MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadH 20
Structure length83 ft (25.3 m)
Longest span78 ft (23.8 m)
Deck width56 ft (17.1 m)
Roadway width50 ft (15.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic47,879 (2023)
Projected traffic78,965 by 2032
Trucks19%
Lanes on structure4
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed0.6 mi (1 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 statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$4.3 million (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was I 495 SB over Water Assabet River built?

It was built in 1963, making it 62 years old in 2025.

What condition is I 495 SB over Water Assabet River in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in July 2023.

How much traffic does I 495 SB over Water Assabet River carry?

About 47,879 vehicles per day (2023 count), of which roughly 19% are trucks.

How long is I 495 SB over Water Assabet River?

The structure is 83 ft (25.3 m) long with a longest span of 78 ft (23.8 m) and a deck 56 ft wide.

Who owns I 495 SB over Water Assabet River?

It is owned by the State Highway Agency.