US Bridges

I 495 SB over ST 1 A/South ST

Fair

Norfolk County, Massachusetts · At ST 1A · Structure no. W460103RYDOTNBI

Built
1966
59 years old
Condition
Fair
inspected November 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
92 ft
1 main span
Daily traffic
49,972
2022 count
Owner
State
State Highway Agency

About this bridge

I 495 SB over ST 1 A/South ST is a steel stringer/multi-beam or girder carrying I 495 SB over ST 1 A/South ST in Norfolk County, Massachusetts. It was built in 1966, so it is 59 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 49,972 vehicles a day, roughly 6% of them trucks, projected to reach 71,068 by 2032. The structure is 92 ft (28 m) long and 56 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI 495 SB
CrossesST 1 A/South ST
LocationAt ST 1A
RouteInterstate 495
CountyNorfolk County
StateMassachusetts
Coordinates42.03992, -71.34521
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.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Approach roadway alignment6: Equal to present minimum criteria
Operating rating60.2 US tons
Inventory rating36 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20 + Mod
Structure length92 ft (28 m)
Longest span86 ft (26.3 m)
Deck width56 ft (17.1 m)
Roadway width53 ft (16.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic49,972 (2022)
Projected traffic71,068 by 2032
Trucks6%
Lanes on structure4
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.2 mi (2 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 proposedWidening of existing bridge without deck rehabilitation
Estimated improvement cost$3.9 million (2025 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I 495 SB over ST 1 A/South ST built?

It was built in 1966, making it 59 years old in 2025.

What condition is I 495 SB over ST 1 A/South 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 November 2023.

How much traffic does I 495 SB over ST 1 A/South ST carry?

About 49,972 vehicles per day (2022 count), of which roughly 6% are trucks.

How long is I 495 SB over ST 1 A/South ST?

The structure is 92 ft (28 m) long with a longest span of 86 ft (26.3 m) and a deck 56 ft wide.

Who owns I 495 SB over ST 1 A/South ST?

It is owned by the State Highway Agency.