US Bridges

I 93 SB Bt 46-57 over TR Orange Line

Fair

Suffolk County, Massachusetts · .5 MI N of JCT I93&US1 · Structure no. B162813BTDOTNBI

Built
1970
55 years old
Condition
Fair
inspected November 2024
Type
Girder and Floorbeam System
Steel
Length
898 ft
11 main spans
Daily traffic
85,975
2023 count
Owner
State
State Highway Agency

About this bridge

I 93 SB Bt 46-57 over TR Orange Line is a steel girder and floorbeam system carrying I 93 SB Bt 46-57 over TR Orange Line in Suffolk County, Massachusetts. It was built in 1970, so it is 55 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 5 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 85,975 vehicles a day, roughly 6% of them trucks, projected to reach 108,498 by 2031. The structure is 898 ft (273.7 m) long and 70 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI 93 SB Bt 46-57
CrossesTR Orange Line
Location.5 MI N of JCT I93&US1
RouteInterstate 93
CountySuffolk County
StateMassachusetts
Coordinates42.37717, -71.075
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.
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 inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating60.3 US tons
Inventory rating36 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialSteel
DeckConcrete, cast-in-place
Main spans11
Design loadHS 20 + Mod
Structure length898 ft (273.7 m)
Longest span82 ft (25 m)
Deck width70 ft (21.3 m)
Roadway width58 ft (17.6 m)
Vertical clearance over deck15 ft (4.7 m)

Traffic and service

Average daily traffic85,975 (2023)
Projected traffic108,498 by 2031
Trucks6%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesRailroad
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 proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$56.9 million (2025 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I 93 SB Bt 46-57 over TR Orange Line built?

It was built in 1970, making it 55 years old in 2025.

What condition is I 93 SB Bt 46-57 over TR Orange Line 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 2024.

How much traffic does I 93 SB Bt 46-57 over TR Orange Line carry?

About 85,975 vehicles per day (2023 count), of which roughly 6% are trucks.

How long is I 93 SB Bt 46-57 over TR Orange Line?

The structure is 898 ft (273.7 m) long with a longest span of 82 ft (25 m) and a deck 70 ft wide.

Who owns I 93 SB Bt 46-57 over TR Orange Line?

It is owned by the State Highway Agency.