US Bridges

I 495 SB over ST133 Andover ST

Fair

Middlesex County, Massachusetts · Rt 495 at Rt 133 · Structure no. T030142JVDOTNBI

Built
1961
64 years old
Condition
Fair
inspected April 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
228 ft
3 main spans
Daily traffic
65,206
2024 count
Owner
State
State Highway Agency

About this bridge

I 495 SB over ST133 Andover ST is a steel stringer/multi-beam or girder carrying I 495 SB over ST133 Andover ST in Middlesex County, Massachusetts. It was built in 1961, so it is 64 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: open, would be posted or closed except for temporary shoring.

It carries about 65,206 vehicles a day, roughly 9% of them trucks, projected to reach 189,516 by 2031. The structure is 228 ft (69.4 m) long and 60 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

CarriesI 495 SB
CrossesST133 Andover ST
LocationRt 495 at Rt 133
RouteInterstate 495
Coordinates42.64278, -71.23222
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
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.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, would be posted or closed except for temporary shoring
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating62.5 US tons
Inventory rating31 US tons

Structure

MaterialSteel
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length228 ft (69.4 m)
Longest span109 ft (33.2 m)
Deck width60 ft (18.3 m)
Roadway width52 ft (15.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic65,206 (2024)
Projected traffic189,516 by 2031
Trucks9%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed3.7 mi (6 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$12.5 million (2025 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I 495 SB over ST133 Andover ST built?

It was built in 1961, making it 64 years old in 2025.

What condition is I 495 SB over ST133 Andover ST 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 2023.

How much traffic does I 495 SB over ST133 Andover ST carry?

About 65,206 vehicles per day (2024 count), of which roughly 9% are trucks.

How long is I 495 SB over ST133 Andover ST?

The structure is 228 ft (69.4 m) long with a longest span of 109 ft (33.2 m) and a deck 60 ft wide.

Who owns I 495 SB over ST133 Andover ST?

It is owned by the State Highway Agency.