US Bridges

I 93 NB Bt 38-46 over I 93 SB Bt 38-46

Fair

Suffolk County, Massachusetts · .7 MI N of JCT US1&I93 · Structure no. B162813DWDOTNBI

Built
1970
55 years old
Condition
Fair
inspected April 2024
Type
Girder and Floorbeam System
Steel
Length
652 ft
8 main spans
Daily traffic
81,000
2020 count
Owner
State
State Highway Agency

About this bridge

I 93 NB Bt 38-46 over I 93 SB Bt 38-46 is a steel girder and floorbeam system carrying I 93 NB Bt 38-46 over I 93 SB Bt 38-46 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 81,000 vehicles a day, roughly 8% of them trucks, projected to reach 117,184 by 2031. The structure is 652 ft (198.7 m) long and 69 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI 93 NB Bt 38-46
CrossesI 93 SB Bt 38-46
Location.7 MI N of JCT US1&I93
RouteInterstate 93
CountySuffolk County
StateMassachusetts
Coordinates42.37536, -71.07302
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 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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment7: Better than present minimum criteria
Operating rating58.5 US tons
Inventory rating35.1 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialSteel
DeckConcrete, cast-in-place
Main spans8
Design loadHS 20
Structure length652 ft (198.7 m)
Longest span82 ft (25 m)
Deck width69 ft (21 m)
Roadway width62 ft (18.9 m)
Vertical clearance over deck16 ft (4.8 m)

Traffic and service

Average daily traffic81,000 (2020)
Projected traffic117,184 by 2031
Trucks8%
Lanes on structure3
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 proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$40.7 million (2025 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I 93 NB Bt 38-46 over I 93 SB Bt 38-46 built?

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

What condition is I 93 NB Bt 38-46 over I 93 SB Bt 38-46 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 2024.

How much traffic does I 93 NB Bt 38-46 over I 93 SB Bt 38-46 carry?

About 81,000 vehicles per day (2020 count), of which roughly 8% are trucks.

How long is I 93 NB Bt 38-46 over I 93 SB Bt 38-46?

The structure is 652 ft (198.7 m) long with a longest span of 82 ft (25 m) and a deck 69 ft wide.

Who owns I 93 NB Bt 38-46 over I 93 SB Bt 38-46?

It is owned by the State Highway Agency.